研究者詳細 - 前田　憲成

論文 - 前田　憲成

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Effect of Photo Irradiation on the Anaerobic Digestion of Waste Sewage Sludge-Reduced Methane and Hydrogen Sulfide Productions 招待有り査読有り国際誌

Toya S., Iriguchi S., Yamaguchi K., Maeda T.

Fermentation 9 ( 11 ) 2023年11月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

Since a large amount of sewage sludge (WSS) is generated daily, exploring effective methods for utilizing WSS is necessary. Although a photo-fermentation system sometimes alters the characteristics of microbial functions, there have been no attempts to perform photo-fermentation using WSS, which is regularly treated via dark fermentation. In this study, the effect of photo-fermentation (photo-irradiation) on anaerobic digestion using WSS was revealed. Photo-irradiation during the anaerobic digestion of WSS significantly reduced the amount of methane and hydrogen sulfide. Methane production was also reduced 5.6-fold at 13 days under light conditions, whereas hydrogen sulfide was consumed almost completely at 6 days. However, it was shown that the activity of sulfate-reducing bacteria in WSS under light treatment increased. Photo-irradiation also stimulated the growth of green sulfur bacteria and induced anoxygenic photosynthesis, via which process the fermented samples turned green in a manner that was correlated with their consumption of hydrogen sulfide. The production of organic acids was lowered in the samples that were irradiated using light. Finally, dark/light switching fermentation was only able to reduce hydrogen sulfide while methane production remained the same. The amounts of methane and hydrogen sulfide were 35 mmol/g VS, and they were undetected at 58 days in photo-irradiated samples compared to the control samples that produced 37 mmol/g VS of methane and 15 ppm/g VS of hydrogen sulfide.

DOI： 10.3390/fermentation9110943

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Quorum quenching of autoinducer 2 increases methane production in anaerobic digestion of waste activated sludge 査読有り国際誌

Sarah Sabidi, Yuki Hoshiko, Toshinari Maeda

Applied Microbiology and Biotechnology ( Springer ) 106 ( 12 ) 4763 - 4774 2022年06月

Evaluating greenhouse gas reduction in Seremban, Malaysia: A pilot study on biogas production from organic municipal solid waste 査読有り国際誌

Samsuri I.A., Yusoff M.Z.M., Hassan M.A., Sharaai A.H., Ramli N., Ahmad Farid M.A., Abd Hamid M.A., Maeda T.

Energy for Sustainable Development 86 2025年06月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）

The growing population causes municipal solid waste (MSW) buildup, which is a major problem. National MSW output in Malaysia is estimated at 1.17 kg per capita. This issue is crucial since 29 Malaysian landfills produce 200 thousand tons of MSW per month, releasing greenhouse gasses (GHGs). Anaerobic digestion (AD) may convert MSW into biogas to lower its organic content for landfill disposal. The AD system aims to produce biogas from domestic organic waste to create a circular economy. This study also surveyed Seremban, Malaysia, inhabitants on MSW composition and disposal. The organic fraction of MSW was subjected to the pilot-scale 500 L AD reactor, resulting in a daily average biogas production of 92–262 L, where a significant proportion of the biogas constituent, ranging from 60 to 70 %, is CH<inf>4</inf>. Biogas production was shown to be enhanced by an increase in feedstock, as seen by a greater daily intake of 5 kg. SimaPro was then used to quantify the resulting GHGs emissions from the AD process. The results indicated a value of 0.215 kgCO<inf>2</inf> equivalent for every 5 kg food waste that underwent processing. The proposed AD system exhibits a remarkable 80 % improvement in GHG emission reduction per kg of food waste processed, in comparison to existing methods. A thorough familiarity with organic waste's make-up and disposal patterns is necessary for its effective implementation. Statistics revealed that only 35.45 % of Seremban residents disposed of MSW daily, and that waste segregation rates were below 50 %. As a percentage of MSW, organic waste account for 55 %, or 0.35 kg/person/day. With a daily capacity of 20 kg for processing food waste, the proposed AD system is highly dependent on a constant organic waste supply. Instead of continuing to be inept at waste management, this effort offered an alternative. MSW poses significant environmental concerns, but the proposed pilot-scale AD system shows promise in addressing these issues and encouraging sustainable habits in local communities. At the very least, this could result in a reduction in MSW sent to landfills and GHG emissions for residents of Seremban.

DOI： 10.1016/j.esd.2025.101718

Scopus

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Genomic insights into pigmented Serratia marcescens strains isolated from patients in northeast Mexico 査読有り国際誌

Sánchez-Pérez M., Andrade A., Flores-Maldonado O., de Anda-Mora K., García-Contreras R., Maeda T., Becerril-García M.A., Tavares-Carreón F.

Microbial Pathogenesis 203 2025年06月

記述言語：英語掲載種別：研究論文（学術雑誌）

Serratia marcescens (SM) is an opportunistic pathogen associated with outbreaks in immunocompromised hosts. While SM is commonly isolated from clinical and environmental sources, prodigiosin production is typically associated with environmental strains rather than clinical isolates. Here, we report the genome sequences of three pigmented SM clinical isolates —HU1848, HU2225, and HU2228— and examine their genomic and phenotypic characteristics. Phylogenetic analysis using 1103 finished public SM genomes revealed that these isolates cluster more closely with environmental SM strains than with those typically associated with clinical settings. Notably, despite their environmental-like genomic background, these isolates harbor multiple virulence genes implicated in colonization and resistance to fertilizers, as well as antimicrobial resistance genes for chloramphenicol, fosfomycin, and tetracycline. MIC determination showed susceptibility to aminoglycosides and fluoroquinolones. Additionally, we observed that the phenolic compound methyl gallate modulates pigment production and motility. The absence of AHL biosynthetic genes in these pigmented strains challenges previous associations between quorum sensing and prodigiosin biosynthesis. These findings suggest that certain SM strains with environmental-like genetic features can persist in clinical settings, underscoring the need to further investigate their potential role in nosocomial infections.

DOI： 10.1016/j.micpath.2025.107456

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Novel insights into indigenous phenol-degrading bacteria from palm oil mill effluent and their potential mechanisms for efficient phenol degradation 査読有り国際誌

Sabri I., Ng K.X., Ku Mohammad Soffi N., Mohd Yusoff M.Z., Nor Muhammad N.A., Ho L.S., Maeda T., Ramli N.

Environmental Technology and Innovation 37 2025年02月

記述言語：英語掲載種別：研究論文（学術雑誌）

Phenol is a toxic pollutant with mutagenic, carcinogenic, and teratogenic properties, necessitating its removal from phenol-contaminated environments. Biodegradation presents a viable solution, with microbial sources commonly found in phenol-contaminated environments, including palm oil mill effluent (POME). However, the indigenous bacteria capable of efficiently metabolizing phenol from POME remain unidentified, with limited knowledge of their composition, potential functions, and mechanisms of phenol degradation. The ability of the phenol-acclimatized mixed culture (PBMC) derived from POME to metabolize phenol was assessed by evaluating its bacterial composition using 16S rRNA amplicon sequencing, followed by predictions of its potential mechanisms. Subsequently, the phenol degradation capability was evaluated through batch cultivations with phenol as the sole carbon source. This was then compared with an isolated phenol degrader from POME, identified as Acinetobacter sp. AL9, whose genetic makeup was revealed through whole-genome sequencing. Well-known phenol degraders thrived in the PBMC, including Acinetobacter (16.75 %), Pseudomonas (10.48 %), and Flavobacterium (10.35 %). This community degraded phenol through seven different pathways, primarily catalyzed by protocatechuate 3,4-dioxygenase via the protocatechuate degradation II (ortho-cleavage pathway). The presence of catechol 1,2-dioxygenase and catechol 2,3-dioxygenase also signified the involvement of catechol ortho-cleavage, and catechol degradation I and II (meta-cleavage) pathways, respectively. The PBMC completely degraded 300 mg/L of phenol more rapidly within 16 hours compared to the isolated Acinetobacter sp. AL9, which took 40 hours. This aligns with AL9’s phenol metabolism, which relies solely on the complete catechol ortho-cleavage pathway. This finding highlights the potential for harnessing the indigenous bacterial mixed culture from POME for efficient phenol bioremediation.

DOI： 10.1016/j.eti.2024.103983

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Microbial Population Dynamics of the Low-strength Partial Nitritation System and Its Correlation of Nitrifiers to the Model-predicted Biomass 査読有り国際誌

Pham T.Y., Maeda T., Sun M., Terashima M., Goel R., Yasui H.

Journal of Water and Environment Technology ( 公益社団法人日本水環境学会 ) 23 ( 2 ) 94 - 106 2025年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

Using a lab-scale activated sludge system equipped with an external selector for suppressing nitrite oxidising organism (NOO), the microbial population dynamics were investigated during about 400 days of the continuous operation. In the varied selector operations and excess sludge withdrawal, the nitrification, partial nitritation, and nitrification loss followed by the recovery of partial nitritation consecutively took place. The DNA analysis with the high-throughput sequencing revealed that only Nitrosomonas spp. retained during the nitritation-nitrification and only Nitrospira spp. could grow in nitrification, respectively. Proteobacteria was the most predominant heterotroph in the main aeration tank, whilst Bacteroidota was abundant in the external selector in association with the reduced microbial diversities. In the external selector, due to the high nitrite and ammonium, the ammonium oxidising organism’s (AOO) inherent enzyme genes (Amo and Hao) per total microbial gene copies were as low as about 50% of that in the main aeration tank. The dynamically calculated AOO and NOO concentrations using the IWA-ASMl-based model could be linearly correlated to both relative abundances in the activated sludge. The correlations suggested that the DNA analysis could be potentially utilised as an alternative tool to estimate the nitrifier biomass of activated sludge instead of performing kinetic modelling.

DOI： 10.2965/jwet.24-136

Scopus

CiNii Research

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Effect of Biochar Addition in Two Different Phases of the Co-Composting of Green Waste and Food Waste: An Analysis of the Process, Product Quality and Microbial Community 査読有り国際誌

Oviedo-Ocaña E.R., Soto-Paz J., Parra-Orobio B.A., Zafra G., Maeda T., Galezo-Suárez A.C., Diaz-Larotta J.T., Sanchez-Torres V.

Waste and Biomass Valorization 2025年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

Green waste (GW) contains lignocellulosic substances that are resistant to degradation and prolong the composting process. Different strategies have been used to improve GW composting, including adding co-substrates and additives like food waste (FW) and biochar (Bc). FW offers advantages such as its constant availability in MSW streams, its high content of readily degradable organic matter, and its contribution of essential nutrients like nitrogen and potassium. On the other hand, Bc is incorporated at the beginning of the process. However, the effect of its addition in the phase of greatest biological activity has not been studied. This article compares the effect on the process, product quality, and the compost microbial community of adding 2% Bc in two different phases of the co-composting GW with food waste (FW). Two treatments were evaluated using the same mixture of substrates (wet/ weight) (i.e., 48%GW + 35%FW + 13%Sawdust + 2% Phosphate Rock + 2%Bc), but Bc was added in the mesophilic phase for T1 and the thermophilic phase for T2. With the addition of Bc at the mesophilic phase, higher temperatures were reached in the thermophilic phase, with a maximum temperature of 52.5 °C for T1 and 47.7 °C for T2. T1 final product had higher nutrient content (i.e., 28.30% TOC, 1.91% TN, and 4.69% TP in T1 compared to 15.80% TOC, 1.14% TN, and 4.29% TP in T2) and achieved a higher fertility index. Streptomyces and Nonomuraea were more abundant in T1 than T2, while Rhizobium, Roseiflexus, and Chloroflexus were significantly more abundant in T2 than in T1. These results suggest that T1 presents a microbial community that is more robust in degrading complex organic materials. This article demonstrated increased biological activity, lignocellulosic degradation, and nutrient content in the product when biochar is added from the beginning of the process.

DOI： 10.1007/s12649-024-02878-6

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Whole genome sequencing of methicillin-resistant Staphylococcus aureus clinical isolates from Terengganu, Malaysia, indicates the predominance of the EMRSA-15 (ST22-SCCmec IV) clone 査読有り国際誌

Che Hamzah A.M., Chew C.H., Al-Trad E.I., Puah S.M., Chua K.H., Nor N.I., Ismail S., Maeda T., Palittapongarnpim P., Yeo C.C.

Scientific Reports 14 ( 1 ) 2024年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

Despite the importance of methicillin-resistant Staphylococcus aureus (MRSA) as a priority nosocomial pathogen, the genome sequences of Malaysian MRSA isolates are currently limited to a small pool of samples. Here, we present the genome sequence analyses of 88 clinical MRSA isolates obtained from the main tertiary hospital in Terengganu, Malaysia in 2016–2020, to obtain in-depth insights into their characteristics. The EMRSA-15 (ST22-SCCmec IV) clone of the clonal complex 22 (CC22) lineage was predominant with a total of 61 (69.3%) isolates. Earlier reports from other Malaysian hospitals indicated the predominance of the ST239 clone, but only two (2.3%) isolates were identified in this study. Two Indian-origin clones, the Bengal Bay clone ST772-SCCmec V (n = 2) and ST672 (n = 10) were also detected, with most of the ST672 isolates obtained in 2020 (n = 7). Two new STs were found, with one isolate each, and were designated ST7879 and ST7883. From the core genome phylogenetic tree, the HSNZ MRSA isolates could be grouped into seven clades. Antimicrobial phenotype-genotype concordance was high (> 95%), indicating the accuracy of WGS in predicting most resistances. Majority of the MRSA isolates were found to harbor more than 10 virulence genes, demonstrating their pathogenic nature.

DOI： 10.1038/s41598-024-54182-x

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Transplant of gut microbiota ameliorates metabolic and heart disorders in rats fed with a hypercaloric diet by modulating microbial metabolism and diversity 査読有り国際誌

Peña-Ocaña B.A., Silva-Flores M., Shotaro T., García-Gálvez L., Hernández-Esquivel L., Robledo-Cadena D.X., Barrera-Oviedo D., Pérez-Torres I., Tostado-Islas O., Maeda T., Rodríguez-Zavala J.S., Marín-Hernández Á., García-Contreras R., Jasso-Chávez R.

Biomedicine and Pharmacotherapy 181 2024年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

Metabolic syndrome (MS) is a cluster of metabolic disorders which have a tight correlation with dysbiosis of gut microbiota (GM) that have to be treated to avoid higher risks for health. In this work, probiotics obtained from healthy cultured GM were provided to rats with metabolic syndrome (MSR) as therapy in treating MS through the correction of dysbiosis. MSR showed obesity, high blood pressure, abnormal blood chemistry parameters and high heart rate respect to control rats (CNTR). Cultivated GM from feces of MSR in media favoring anaerobic species, showed dysbiosis as judged by differences in the 16S rRNA metabarcoding analysis and by affected intermediary metabolism (methane and SCFA production, nutrients consumption and enzyme activities) compared to CNTR. The metabarcoding analysis of cultured healthy GM identified 211 species, which were further transplanted alive in MSR once a week for 9 weeks. Thereafter, in transplanted MSR the excess of Clostridium and Lactobacillus diminished, while Prevotella, Eubacterium, Faecalibacterium and methanogens, among others increased, leading to the recovery of the microbial metabolic capacity. The presence of butyric acid-producing bacteria in the transplanted GM correlated with increased levels of anti-inflammatory cytokines. Therefore, transplanted MSR recovered the normal levels of weight, blood glucose, triglycerides and cholesterol as well as the heart function. Data suggested that the great diversity of species contained in the GM transplanted restored the microbial metabolism, consuming excessive nutrients and secondary metabolites produced by MS. The use of cultivated GM as probiotics may be a safer alternative for the treatment of different diseases.

DOI： 10.1016/j.biopha.2024.117667

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Novel Insights into Cr(VI)-Induced Rhamnolipid Production and Gene Expression in Pseudomonas aeruginosa RW9 for Potential Bioremediation 査読有り国際誌

Arisah F.M., Ramli N., Ariffin H., Maeda T., Farid M.A.A., Yusoff M.Z.M.

Journal of Microbiology and Biotechnology 34 ( 9 ) 1877 - 1889 2024年09月

記述言語：英語掲載種別：研究論文（学術雑誌）

Rhamnolipid (RL) is renowned for its efficacy in bioremediating several types of organic and metal contaminants. Nevertheless, there has been a scarcity of studies specifically examining the relationship between this substance and metals, especially in terms of their impact on RL formation and the underlying interaction processes. This study addresses this gap by investigating the RL mechanism in Cr (VI) remediation and evaluating its effect on RL production in Pseudomonas aeruginosa RW9. In this study, P. aeruginosa RW9 was grown in the presence of 10 mg l-1 Cr (VI). We monitored RL yield, congeners distribution, and their ratios, as well as the transcriptional expression of the RL-encoded genes: rhlA, rhlB, and rhlC. Our results revealed that RL effectively reduced Cr (VI) to Cr (III), with RL yield increasing threefold, although with a slight delay in synthesis compared to control cells. Furthermore, Cr (VI) exposure induced the transcriptional expression of the targeted genes, leading to a significant increase in di-RL production. The findings confirm that Cr (VI) significantly impacts RL production, altering its structural compositions and enhancing the transcriptional expression of RL-encoded genes in P. aeruginosa RW9. This study represents a novel exploration of Cr (VI)'s influence on RL production, providing valuable insights into the biochemical pathways involved and supporting the potential of RL in Cr (VI) bioremediation.

DOI： 10.4014/jmb.2406.06034

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Antibacterial mechanism of Pseudomonas aeruginosa UKMP14T rhamnolipids against multidrug resistant Acinetobacter baumannii 査読有り国際誌

Firdose A., Maeda T., Sukri M.A.M., Yasin N.H.M., Sabturani N., Aqma W.S.

Microbial Pathogenesis 193 2024年08月

記述言語：英語掲載種別：研究論文（学術雑誌）

Rhamnolipids, a major category of glycolipid biosurfactant, have recently gained enormous attention in medical field because of their relevance as effective antibacterial agents against a wide variety of pathogenic bacteria. Our previous studies have shown that rhamnolipids from an environmental isolate of Pseudomonas aeruginosa UKMP14T possess antibacterial, anti-adhesive and anti-biofilm activity against multidrug-resistant ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter sp.) pathogens. However, the mechanism of their antibacterial action remains unclear. Thus, this study aimed to elucidate the mechanism of the antibacterial action of P. aeruginosa UKMP14T rhamnolipids by studying the changes in cells of one of the ESKAPE pathogens, Acinetobacter baumannii, which is the most difficult strain to kill. Results revealed that rhamnolipid treatment rendered A. baumannii cells more hydrophobic as evaluated through contact angle measurements. It also induced the release of cellular proteins measuring 510 μg/mL at a rhamnolipid concentration of 1000 μg/mL. In addition, rhamnolipids were found to be bactericidal in their action as they could permeate the inner membranes, leading to a leak-out of nucleotides. More than 50 % of the cells were found to be killed upon 1000 μg/mL rhamnolipid treatment as observed through fluorescence microscopy. Other cellular changes such as irregular shape and size, membrane perturbations, clumping, shrinkage and physical damage were clearly visible in SEM, FESEM and laser micrographs. Furthermore, rhamnolipid treatment inhibited the levels of acyl-homoserine lactones (AHLs) in A. baumannii, which are vital for their biofilm formation and virulence. The obtained results indicate that P. aeruginosa UKMP14T rhamnolipids target outer and inner bacterial membranes through permeation, including physical damage to the cells, leading to cell leakage. Furthermore, AHL inhibition appears to be the mechanism behind their anti-biofilm action. All these observations can be correlated to rhamnolipids’ antibacterial effect against A. baumannii.

DOI： 10.1016/j.micpath.2024.106743

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An innovative temperature control strategy to improve optically pure L-lactic acid production from food waste 査読有り国際誌

Wang X., Sun H., Narita J.y., Ma X., Gao M., Maeda T., Wang Q.

Process Biochemistry 141 112 - 117 2024年06月

記述言語：英語掲載種別：研究論文（学術雑誌）

Fermentation of food waste to lactic acid (LA) is a strategy for resource recovery. However, the poor yield and optical activity (OA) of L-lactic acid (L-LA) are major bottlenecks for such efforts. This study focuses on enhancing L-LA yield and optical purity from the food waste without sterilization and inoculation at pilot-scale. First, the effects of temperature on LA production were explored. A higher LA yield but lower purity was obtained under mesophilic conditions, whereas the opposite results were represented at high temperature. On the basis of these findings, a novel two-stage temperature regulation strategy was developed that combined the benefits of both temperature conditions. This strategy not only ensured a L-LA yield of 0.371 g/g volatile solid, but also achieved a high optical purity of 98.0%. The underlying mechanism is that high temperature could enrich L-lactic acid bacteria (LAB) and inhibit LAB producing both L- and D-LA. Overall, this innovative strategy may be well-suited for generating optically pure L-LA from food waste fermentation.

DOI： 10.1016/j.procbio.2024.02.011

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Improved complete genome sequence of Bdellovibrio bacteriovorus 109J, a widely studied laboratory strain of predatory bacteria 査読有り

Hoshiko Y., Okuno M., Yamamoto T., Maeda T., Ogura Y.

Microbiology Resource Announcements 13 ( 6 ) 2024年06月

記述言語：英語掲載種別：研究論文（学術雑誌）

The complete genome sequence of Bdellovibrio bacteriovorus 109J, a well-studied laboratory strain of predatory bacteria, first determined in 2014. Here we report an improved complete genome sequence of B. bacteriovorus 109J, incorporating 16 assembly and 87 nucleotide corrections. This revised genome will be helpful to studies on the predatory bacteria.

DOI： 10.1128/mra.01296-23

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Rhamnolipids production by Pseudomonas aeruginosa RW9 using palm oil mill effluent sludge oil as a carbon source 査読有り国際誌

Mohd Asmadi N.A.N., Zee K.M., Baskaran S.M., Ariffin H., Wasoh H., Maeda T., Hassan M.A., Zakaria M.R.

Biocatalysis and Agricultural Biotechnology 57 2024年04月

記述言語：英語掲載種別：研究論文（学術雑誌）

The production of biosurfactants has garnered considerable attention in recent years due to their unique properties, which include the ability to enhance oil solubility in water, reduce surface tension, and exhibit low environmental toxicity. In this study, we investigated the production of biosurfactants by Pseudomonas aeruginosa RW9, using a renewable and non-food competitive, palm oil mill effluent (POME) sludge oil as a carbon source. Various carbon and nitrogen sources were introduced into the mineral salt medium to optimize biosurfactant production. The results demonstrated that P. aeruginosa RW9 successfully generated 1.57 g/L of rhamnolipids (RLs) biosurfactant. Liquid chromatography-mass spectrometry (LC-MS) analysis confirmed the presence of mono-RLs and di-RLs congeners. Furthermore, the RLs produced from POME sludge oil exhibited a significant reduction in surface tension, reaching 28.55 mN/m, and demonstrated efficient emulsification of diesel, with an emulsion index of up to 56.6 %. This research underscores the promising potential of using POME sludge oil as a sustainable substrate for RLs production. This approach not only adds value to a vastly available resource but also contributes to the production of environmentally friendly biochemicals.

DOI： 10.1016/j.bcab.2024.103069

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Identification of skin bacterial profiles of early deceased bodies and the rto post-mortem interval 査読有り国際誌

Chong C.K., Emamjomeh M., Joseph N., Siew S.F., Maeda T., Mustapha N.A., Hoshiko Y., Muthanna A., Amin-Nordin S.

Tropical Biomedicine 41 ( 1 ) 109 - 117 2024年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

Post-mortem microbiology (PMM) is an important tool in identifying possible causes of sudden unexpected death, as an infectious cause is highly suspected. However, contamination is a major problem in microbiology, and this has increased the difficulty determining the true pathogen that contributes to death in post-mortem cases. Skin commensals are common contaminants in blood cultures. This study was conducted to investigate the skin flora on early deceased bodies and observe the bacteria detected at different post-mortem intervals (PMIs). As blood is usually drawn from the neck and femoral sites for PMM examination, the two body sites were chosen as the sampling sites. Skin swab samples from the neck and femoral (n=80) of each early deceased body were collected by sterile cotton swabs. DNA was extracted from the swabs and then subjected to high-throughput 16S rRNA sequencing by using the Illumina MiSeq platform. Staphylococcus was found to be the most dominant genus in both neck and femoral sites. LEfSe results showed that Cutibacterium is significantly different at the neck site while Corynebacterium is more abundant at femoral site. There are significant differences at genus level between PMI<5H and PMI>5H at both neck and femoral sites. The findings of the present study may act as a reference for microbiologists and forensic pathologists when mixed growth or contamination occurs in post-mortem blood cultures.

DOI： 10.47665/tb.41.1.013

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CO2 Sequestration by Thermophilic Enriched Methanogens in Activated Sludge for Methane Production 査読有り

Koya Masahiro, Koyakumaru Saki, Maeda Toshinari

環境バイオテクノロジー学会誌 ( NPO法人環境バイオテクノロジー学会 ) 24 ( 1 ) 97 - 103 2024年01月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

In this study, we examined the anaerobic incubation of waste-activated sludge (WAS) under thermophilic conditions. First, we reconfirmed CO2 sequestration using WAS without any enrichment process at different temperatures under mixed gases (CO2:H2 = 1:4). We observed that the methanogens, which were previously enriched at 37°C, displayed strong CO2 sequestration at an early incubation time. Although CO2 sequestration at 60°C showed the largest impact after 6 days, no methane production was observed at each thermophilic condition within 4 days. Therefore, we enriched methanogens using a novel WAS protocol for 10 days under nitrogen gas under thermophilic conditions. These methanogens displayed better CO2 sequestration than the original strain at 37°C. Moreover, methane production by the thermophilic methanogens was due to the hydrogenotrophic pathway rather than the acetoclastic one because low methanogenic activity from acetate was observed. Microbial community structure analysis showed that the Methanothermobacter genus belonging to hydrogenotrophic methanogens was predominant among the thermophilic enriched methanogens at 60°C. Taken together, the thermophilic methanogens can be a useful tool to sequestrate CO2 efficiently.

DOI： 10.50963/jenvbio.24.1_97

CiNii Research

Pseudomonas aeruginosa-mediated cr(VI) bioremediation: mechanistic insights and future directions 査読有り国際誌

Mat Arisah F., Ramli N., Ariffin H., Maeda T., Ahmad Farid M.A., Yusoff M.Z.M.

Bioremediation Journal 2024年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

Contamination of hexavalent chromium (Cr(VI)) is a major environmental issue since it has the ability to cause cancer and genetic mutations. Bioremediation techniques using Pseudomonas aeruginosa have emerged as potential methods to tackle this problem. This study offers a thorough examination of the underlying mechanisms and potential future paths in the process of P. aeruginosa-mediated Cr(VI) remediation. Herein, the strategies used by P. aeruginosa were examined for the removal of Cr(VI) via processes such as biosorption, intracellular reduction, and extracellular metabolism. In addition, the function of extracellular polymeric substances (EPS) in capturing and isolating Cr(VI) was studied and the possibility of using genetic engineering techniques to improve P. aeruginosa’s ability to remove Cr(VI) from the environment was explored. In addition, we investigate the difficulties related to the use of P. aeruginosa for Cr(VI) bioremediation, such as environmental conditions and the presence of other microorganisms, and suggest potential areas for further study. These include the development of bioremediation strategies using consortia of microorganisms and the incorporation of nanomaterials to improve the removal of Cr(VI). This study seeks to enhance the development of sustainable solutions for remediating Cr(VI) by integrating existing information and identifying future research directions, with a focus on employing P. aeruginosa.

DOI： 10.1080/10889868.2024.2420071

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Assessing microbial biodiversity in oil palm seedlings using oil palm waste compost mixed media 査読有り国際誌

Salamat S.S., Yusoff M.Z.M., Hassan M.A., Zainudin M.H.M., Shirai Y., Mohd Hanif A.H., Norizan M.S., Arisah F.M., Farid M.A.A., Maeda T., Mat Isa M.N., Abu Bakar M.F.

International Journal of Recycling of Organic Waste in Agriculture 13 ( Special Issue ) 2024年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

Purpose: The oil palm nursery plays a pivotal role in ensuring optimal replanting materials for sustained productivity. However, conventional practices that rely exclusively on inorganic fertilizers can degrade soil over time, highlighting the need to reassess planting materials. This study examines the impact of incorporating compost into soil media on oil palm seedling development in primary nurseries. Method: The study compared microbial biodiversity in soil media with compost amendments by employing DNA sequencing to assess microbial communities. The analysis focused on bacterial species richness and the prevalence of key phyla, including Proteobacteria, Actinobacteria, Acidobacteria, and others. Results: The compost-amended media (T2) demonstrated significantly higher microbial biodiversity, with 60,769 sequences compared to 45,741 sequences in media containing only soil and inorganic fertilizer (T1). This compost-enriched media notably increased bacterial species richness, particularly benefiting nutrient-cycling bacteria such as Proteobacteria and Actinobacteria. While Acidobacteria showed sensitivity to compost, other phyla like Firmicutes, Planctomycetes, and Chloroflexi remained stable under the nutrient dynamics of elevated organic content. Streptomyces, known for its metabolic versatility, dominated across all media compositions. The co-occurrence of Bacteroidetes and Acidobacteria in compost-treated soils suggested pH stability that supports plant growth and ecosystem resilience. Conclusion: Integrating compost into nursery media significantly enhances microbial biodiversity and dynamics, particularly favoring beneficial nutrient-cycling bacteria. This suggests that compost amendments can serve as a viable pathway for improving oil palm nursery practices, promoting sustainable soil management, and ensuring long-term productivity.

DOI： 10.57647/ijrowa-m2gt-yd26

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Impact of antibiotics on methane produced from cellulose 査読有り国際誌

Zhu Q., Maeda T., Chen C., Wang Y., Tan F., Hu G., He M.

Journal of Renewable and Sustainable Energy 15 ( 6 ) 2023年11月

記述言語：英語掲載種別：研究論文（学術雑誌）

Enhancing production of methane from cellulose is of utmost importance to improve the fermentation efficiency of lignocellulosic biomass. Antibiotics have demonstrated their ability to stimulate anaerobic digestion (AD) by influencing micro-organism activity. However, there has been limited research on the specific effect of antibiotics on cellulose AD. In this study, we investigated the impact of three antibiotics—tetracycline (TC), cephalexin (CLX), and azithromycin (AZM)—on cellulose AD when inoculated with waste sewage sludge. The results revealed that the presence of AZM and TC led to significantly higher methane yields, with increases of 51.94% and 34.96%, respectively, during a 20-day AD period. In contrast, the presence of CLX resulted in a 23.95% lower methane yield compared to the control. Furthermore, detailed analyses indicated that AZM had a positive influence on cellulose AD at all stages, including methanogenesis, acidogenesis/acetogenesis, and hydrolysis. On the other hand, TC primarily promoted AD during the methanogenesis stage. These findings collectively offer valuable guidance for efficiently transforming the energy potential of lignocellulosic wastes.

DOI： 10.1063/5.0175655

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Insights into bacterial community metatranscriptome and metabolome in river water influenced by palm oil mill effluent final discharge 査読有り国際誌

Sharuddin S.S., Ramli N., Yusoff M.Z.M., Muhammad N.A.N., Ho L.S., Maeda T.

Journal of applied microbiology 134 ( 10 ) 2023年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

AIMS: This study aimed to investigate the effect of palm oil mill effluent (POME) final discharge on the active bacterial composition, gene expression, and metabolite profiles in the receiving rivers to establish a foundation for identifying potential biomarkers for monitoring POME pollution in rivers. METHODS AND RESULTS: The POME final discharge, upstream (unpolluted by POME), and downstream (effluent receiving point) parts of the rivers from two sites were physicochemically characterized. The taxonomic and gene profiles were then evaluated using de novo metatranscriptomics, while the metabolites were detected using qualitative metabolomics. A similar bacterial community structure in the POME final discharge samples from both sites was recorded, but their composition varied. Redundancy analysis showed that several families, particularly Comamonadaceae and Burkholderiaceae [Pr(>F) = 0.028], were positively correlated with biochemical oxygen demand (BOD5) and chemical oxygen demand (COD). The results also showed significant enrichment of genes regulating various metabolisms in the POME-receiving rivers, with methane, carbon fixation pathway, and amino acids among the predominant metabolisms identified (FDR < 0.05, PostFC > 4, and PPDE > 0.95). This was further validated through qualitative metabolomics, whereby amino acids were detected as the predominant metabolites. CONCLUSIONS: The results suggest that genes regulating amino acid metabolism have significant potential for developing effective biomonitoring and bioremediation strategies in river water influenced by POME final discharge, fostering a sustainable palm oil industry.

DOI： 10.1093/jambio/lxad219

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Exoprotease exploitation and social cheating in a Pseudomonas aeruginosa environmental lysogenic strain with a noncanonical quorum sensing system 査読有り国際誌

Huelgas-Mendez D., Cazares D., Alcaraz L.D., Ceapã C.D., Cocotl-Yañez M., Shotaro T., Maeda T., Fernández-Presas A.M., Tostado-Islas O., González-Vadillo A.L., Limones-Martínez A., Hernandez-Cuevas C.E., González-García K., Jimenez-García L.F., Martínez R.L., Santos-López C.S., Husain F.M., Khan A., Arshad M., Kokila K., Wood T.K., García-Contreras R.

FEMS Microbiology Ecology 99 ( 9 ) 2023年09月

記述言語：英語掲載種別：研究論文（学術雑誌）

Social cheating is the exploitation of public goods that are costly metabolites, like exoproteases. Exoprotease exploitation in Pseudomonas aeruginosa has been studied in reference strains. Experimental evolution with reference strains during continuous growth in casein has demonstrated that nonexoprotease producers that are lasR mutants are selected while they behave as social cheaters. However, noncanonical quorum-sensing systems exist in P. aeruginosa strains, which are diverse. In this work, the exploitation of exoproteases in the environmental strain ID4365 was evaluated; ID4365 has a nonsense mutation that precludes expression of LasR. ID4365 produces exoproteases under the control of RhlR, and harbors an inducible prophage. As expected, rhlR mutants of ID4365 behave as social cheaters, and exoprotease-deficient individuals accumulate upon continuous growth in casein. Moreover, in all continuous cultures, population collapses occur. However, this also sometimes happens before cheaters dominate. Interestingly, during growth in casein, ID4565's native prophage is induced, suggesting that the metabolic costs imposed by social cheating may increase its induction, promoting population collapses. Accordingly, lysogenization of the PAO1 lasR mutant with this prophage accelerated its collapse. These findings highlight the influence of temperate phages in social cheating.

DOI： 10.1093/femsec/fiad086

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Profiling bacterial communities and foodborne pathogens on food-associated surface following contact with raw beef, chicken and pork using 16S amplicon metagenomics 査読有り国際誌

Emamjomeh M., Mohd Hashim A., Abdul-Mutalib N.A., Khairil Mokhtar N.F., Mustapha N.A., Maeda T., Amin-Nordin S.

Food Control 149 2023年07月

記述言語：英語掲載種別：研究論文（学術雑誌）

Meat products are commonly associated with foodborne diseases outbreak. Bacteria have been long used as a hygienic indicator in the food industry. Food-contacted surfaces could be the source of contamination causing foodborne illness, particularly when involving raw meats. Hence, improving knowledge about bacteria that remains on meat-contacted surfaces can be influential in determining appropriate guidelines for food safety. This study aimed firstly to determine bacterial community structure and diversity. Secondly, to determine taxa co-occurrence network and differentially abundant bacteria and finally, to predict the functional profiles of bacterial communities residing on the food-associated surfaces used in industrial food preparation areas, i.e., aluminum tray, following contact with beef, chicken, and pork using 16S rRNA amplicon metagenomics on the Illumina MiSeq system. The most abundant bacteria on meat-contacted surfaces were determined, and Acinetobacter and Pseudomonas were among the dominant bacteria in all meat types. Chicken-contacted trays showed the highest species richness, followed by pork and beef, with a significant difference. The chicken-contacted tray bacterial community was significantly different from other groups. The co-occurrence network was predicted, and hub nodes were determined. Low-abundance bacteria have been proven to have a significant function in networks. Some of the hub nodes were potential human pathogens or antibiotic-resistant. In addition, bacterial markers were determined; some were human pathogens, such as Shewanella in chicken, Staphylococcus in beef, and Klebsiella in pork. Although the predicted metagenomic functions were not significantly different, some were related to human diseases and resistance to antibiotics or disinfectants. In conclusion, bacterial pathogens were found on aluminum trays despite standard storage practices, demonstrating the need for proper hygiene instructions and regular cleaning of food preparation facilities and equipment to prevent cross-contamination. This study detailed bacterial taxa on meat-contacted trays, and the findings are critical to improving foodborne pathogen decontamination and developing safer food handling guidelines and standards. Radiation, heat, and chemical approaches are said to be influential in preventing contamination.

DOI： 10.1016/j.foodcont.2023.109698

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Positive effect of antibiotics on methane production from corn straw 査読有り

Zhu Q., Maeda T., Song J., Yang Z., Zhang X., He M., Hu G.

Biocatalysis and Agricultural Biotechnology 50 2023年07月

記述言語：英語掲載種別：研究論文（学術雑誌）

Anaerobic digestion (AD) of corn straw (CS) inoculated with waste sewage sludge (WSS) is a promising approach for energy utilization of both lignocellulosic wastes and WSS. However, few studies about the effect of antibiotics contained in WSS on AD of CS are reported, which hinders the efficient conversion from CS to methane (CH4). Antibiotics including tetracycline (TC) and azithromycin (AZM) were used to evaluate their effects on AD of CS inoculated with WSS in this study. As results, the reactor with AZM addition achieved 167.67 mL/g VS CH4 yield, which was increased 65.22% compared with CTRL (without any antibiotics addition, 101.48 mL/g VS CH4 yield) by playing roles at the hydrolysis, acidogenesis/acetogenesis and methanogenesis stages during 20 days of AD. Similarly, addition of TC performed 25.38% (127.27 mL/g VS) higher CH4 yield than CTRL mainly by promoting the acidogenesis/acetogenesis and methanogenesis stages. Specifically, phyla Bacteroidetes, Actinobacteria and genera Methanosarcina, Methanobrevibacter were considered as functional microorganisms for AD of CS with AZM addition. Results from this study provide a new insight for enhancing CH4 yield from CS.

DOI： 10.1016/j.bcab.2023.102732

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Photosynthetic microbial desalination cell (PhMDC) using Chlamydomonas sp. (UKM6) and Scenedesmus sp. (UKM9) as biocatalysts for electricity production and water treatment 査読有り国際誌

Nadzri N.A.A., Mohd Yasin N.H., Abu Bakar M.H., Thanakodi S., Salehmin M.N.I., Takriff M.S., Ni Aznan M.F., Maeda T.

International Journal of Hydrogen Energy 48 ( 31 ) 11860 - 11873 2023年04月

記述言語：英語掲載種別：研究論文（学術雑誌）

A current Microbial Desalination Cell (MDC) system often uses chemicals or air cathodes that are toxic and impractical for scalable applications. This work presents the MDC performance that utilized microalgae species Chlamydomonas sp. (UKM6) and Scenedesmus sp. (UKM9). These species supported the role of the terminal electron acceptor in the cathode chamber of photosynthetic MDCs (PhMDC). The results showed that PhMDC-UKM9 and UKM6 produced 1942 mW/m3 and 1714 mW/m3 power densities with 44% and 32% desalination rates, respectively. The desalination of salt concentration (35 g/L) was approaching the practical application of seawater. Both UKM6 and UKM9 achieved chemical oxygen demand (COD) removal in the anode chamber by 49% and 53%, respectively. 16S microbial community analysis in anolyte revealed phylum Firmicutes as the dominion community. This study demonstrated that the local microalgae species integrate power production, wastewater treatment, and water purification through PhMDC operation, comparable with other studies using commercial microalgae.

DOI： 10.1016/j.ijhydene.2023.01.142

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Simultaneous detection of various pathogenic Escherichia coli in water by sequencing multiplex PCR amplicons 査読有り国際誌

Suzuki Y., Shimizu H., Tamai S., Hoshiko Y., Maeda T., Nukazawa K., Iguchi A., Masago Y., Ishii S.

Environmental Monitoring and Assessment 195 ( 2 ) 2023年02月

記述言語：英語掲載種別：研究論文（学術雑誌）

Waterborne diseases due to pathogen contamination in water are a serious problem all over the world. Accurate and simultaneous detection of pathogens in water is important to protect public health. In this study, we developed a method to simultaneously detect various pathogenic Escherichia coli by sequencing the amplicons of multiplex PCR. Our newly designed multiplex PCR amplified five genes for pathogenic E. coli (uidA, stx1, stx2, STh gene, and LT gene). Additional two PCR assays (for aggR and eae) were also designed and included in the amplicon sequencing analysis. The same assays were also used for digital PCR (dPCR). Strong positive correlations were observed between the sequence read count and the dPCR results for most of the genes targeted, suggesting that our multiplex PCR-amplicon sequencing approach could provide quantitative information. The method was also successfully applied to monitor the level of pathogenic E. coli in river water and wastewater samples. The approach shown here could be expanded by targeting genes for other pathogens.

DOI： 10.1007/s10661-022-10863-6

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Novel cyclic undecapeptides immobilized on reduced graphene oxide surface for enhanced antibacterial properties 査読有り

Farrag H.N., Zheng A.L.T., Sabidi S., Wu Y., Ikeno S., Maeda T., Andou Y., Kato T.

International Journal of Environmental Science and Technology 2023年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

The incorporation of antimicrobial peptides (AMPs) in graphene-based materials is a growing strategy to overcome the shortcomings presented by conventional antimicrobial nanomaterials derived from metal/metal oxide. In this study, novel cyclic undecapeptides CH1 and CW2 (KRQRFYFRQRK and QNKRFYFRKNQ, respectively) were successfully synthesized. The cyclic peptides were then immobilized on the reduced graphene oxide (rGO) surface using a water-soluble carbodiimide (EDCI/HCl) linker. The structural, morphology, and chemical characterizations of the antimicrobial graphene material were carried out using SEM, Raman, FTIR, XRD, and XPS. From our result, the peptide/rGO composite showed an improved antibacterial effect towards gram-positive (Staphylococcus aureus) and gram-negative (Pseudomonas aeruginosa). The enhanced antibacterial property is attributed to the synergistic effect of the sharp edges of rGO and the amphipathic moieties of the cyclic peptides.

DOI： 10.1007/s13762-023-05035-z

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Resistance against two lytic phage variants attenuates virulence and antibiotic resistance in Pseudomonas aeruginosa 査読有り国際誌

García-Cruz J.C., Rebollar-Juarez X., Limones-Martinez A., Santos-Lopez C.S., Toya S., Maeda T., Ceapă C.D., Blasco L., Tomás M., Díaz-Velásquez C.E., Vaca-Paniagua F., Díaz-Guerrero M., Cazares D., Cazares A., Hernández-Durán M., López-Jácome L.E., Franco-Cendejas R., Husain F.M., Khan A., Arshad M., Morales-Espinosa R., Fernández-Presas A.M., Cadet F., Wood T.K., García-Contreras R.

Frontiers in Cellular and Infection Microbiology 13 2023年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

Background: Bacteriophage therapy is becoming part of mainstream Western medicine since antibiotics of clinical use tend to fail. It involves applying lytic bacteriophages that self-replicate and induce cell lysis, thus killing their hosts. Nevertheless, bacterial killing promotes the selection of resistant clones which sometimes may exhibit a decrease in bacterial virulence or antibiotic resistance. Methods: In this work, we studied the Pseudomonas aeruginosa lytic phage φDCL-PA6 and its variant φDCL-PA6α. Additionally, we characterized and evaluated the production of virulence factors and the virulence in a Galleria mellonella model of resistant mutants against each phage for PA14 and two clinical strains. Results: Phage φDCL-PA6α differs from the original by only two amino acids: one in the baseplate wedge subunit and another in the tail fiber protein. According to genomic data and cross-resistance experiments, these changes may promote the change of the phage receptor from the O-antigen to the core lipopolysaccharide. Interestingly, the host range of the two phages differs as determined against the Pseudomonas aeruginosa reference strains PA14 and PAO1 and against nine multidrug-resistant isolates from ventilator associated pneumonia. Conclusions: We show as well that phage resistance impacts virulence factor production. Specifically, phage resistance led to decreased biofilm formation, swarming, and type III secretion; therefore, the virulence towards Galleria mellonella was dramatically attenuated. Furthermore, antibiotic resistance decreased for one clinical strain. Our study highlights important potential advantages of phage therapy’s evolutionary impact that may be exploited to generate robust therapy schemes.

DOI： 10.3389/fcimb.2023.1280265

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Complete genome sequence of Paenibacillus sp. VCA1 isolated from crater lake of the El Chichón Volcano 査読有り国際誌

Martínez-López N.A., Peña-Ocaña B.A., García-Contreras R., Maeda T., Rincón-Rosales R., Cazares A., Hoshiko Y., Ruíz-Valdiviezo V.M.

Microbiology Resource Announcements 12 ( 11 ) 2023年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

We report the complete genome of Paenibacillus sp. strain VCA1, which was isolated from sediment from El Chichón Volcano. This genome consists of 6,690,819 bp and 6,312 coding sequences, with 51.8% G+C content. Whole-genome sequencing was performed to explore the strain's biocontrol and plant growth promotion properties.

DOI： 10.1128/MRA.00583-23

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CRISPR-Cas Controls Cryptic Prophages 査読有り国際誌

Song S., Semenova E., Severinov K., Fernández-García L., Benedik M.J., Maeda T., Wood T.K.

International Journal of Molecular Sciences 23 ( 24 ) 2022年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

The bacterial archetypal adaptive immune system, CRISPR-Cas, is thought to be repressed in the best-studied bacterium, Escherichia coli K-12. We show here that the E. coli CRISPR-Cas system is active and serves to inhibit its nine defective (i.e., cryptic) prophages. Specifically, compared to the wild-type strain, reducing the amounts of specific interfering RNAs (crRNA) decreases growth by 40%, increases cell death by 700%, and prevents persister cell resuscitation. Similar results were obtained by inactivating CRISPR-Cas by deleting the entire 13 spacer region (CRISPR array); hence, CRISPR-Cas serves to inhibit the remaining deleterious effects of these cryptic prophages, most likely through CRISPR array-derived crRNA binding to cryptic prophage mRNA rather than through cleavage of cryptic prophage DNA, i.e., self-targeting. Consistently, four of the 13 E. coli spacers contain complementary regions to the mRNA sequences of seven cryptic prophages, and inactivation of CRISPR-Cas increases the level of mRNA for lysis protein YdfD of cryptic prophage Qin and lysis protein RzoD of cryptic prophage DLP-12. In addition, lysis is clearly seen via transmission electron microscopy when the whole CRISPR-Cas array is deleted, and eliminating spacer #12, which encodes crRNA with complementary regions for DLP-12 (including rzoD), Rac, Qin (including ydfD), and CP4-57 cryptic prophages, also results in growth inhibition and cell lysis. Therefore, we report the novel results that (i) CRISPR-Cas is active in E. coli and (ii) CRISPR-Cas is used to tame cryptic prophages, likely through RNAi, i.e., unlike with active lysogens, active CRISPR-Cas and cryptic prophages may stably co-exist.

DOI： 10.3390/ijms232416195

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Impaired glucose metabolism by deleting the operon of hydrogenase 2 in Escherichia coli 査読有り国際誌

Shekhar C., Maeda T.

Archives of Microbiology 204 ( 10 ) 2022年10月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）

Although Escherichia coli has four hydrogenases, their definite roles in fermentation are still not clear. In this study, all the operon deletion mutants of E.coli hydrogenases (∆hya, ∆hyb, ∆hyc, or ∆hyf) were constructed to evaluate the hydrogen metabolism in comparison to their respective single-gene deletion mutants of large subunits (∆hyaB, ∆hybC, ∆hycE, and ∆hyfG). Besides the hyc operon mutant that expectedly showed no hydrogen synthesis, the hyb operon mutant showed low hydrogen production and demonstrated significantly reduced growth under anaerobic conditions. The present work also provided first-hand data where deleterious effects of operon deletion were compared with single-gene deletion mutations and the results showed that the former type of deletion was found to cause more prominent phenotypic effects than the latter one. Interestingly, hyb operon mutant was remarkably distinct from other operon mutants, specifically in its inability to utilize glucose under both aerobic and anaerobic conditions. Further studies on this mutant revealed a significant reduction of the total intracellular ATP and NADH concentrations, which could explain its impaired glucose metabolism. In this way, Hyd-2 was verified as crucial not only in glucose metabolism but also in energy balance and redox homeostasis of the cells. Furthermore, a decreased expression of glucose metabolism-associated genes, particularly ppc and pykA, indicated their regulation by hyb operon, and thereby, glucose consumption. Moreover, the transcriptional changes in this mutant indicated the wide genomic connectivity of hyb operon to other metabolisms.

DOI： 10.1007/s00203-022-03245-6

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Cultivation of gastrointestinal microbiota in a new growth system revealed dysbiosis and metabolic disruptions in carcinoma-bearing rats 査読有り国際誌

Peña-Ocaña B.A., Hoshiko Y., Silva-Flores M., Maeda T., Pérez-Torres I., García-Contreras R., Gutiérrez-Sarmiento W., Hernández-Esquivel L., Marín-Hernández Á., Sánchez-Thomas R., Saavedra E., Rodríguez-Zavala J.S., Jasso-Chávez R.

Frontiers in Microbiology 13 2022年09月

記述言語：英語掲載種別：研究論文（学術雑誌）

A challenge in the study of gastrointestinal microbiota (GITm) is the validation of the genomic data with metabolic studies of the microbial communities to understand how the microbial networks work during health and sickness. To gain insights into the metabolism of the GITm, feces from healthy and sick rats with cancer were inoculated in a defined synthetic medium directed for anaerobic prokaryote growth (INC-07 medium). Significant differences between cultures of healthy and sick individuals were found: 1) the consumption of the carbon source and the enzyme activity involved in their catabolism (e.g., sucrase, lactase, lipases, aminotransferases, and dehydrogenases); 2) higher excretion of acetic, propionic, isobutyric, butyric, valeric, and isovaleric acids; 3) methane production; 4) ability to form biofilms; and 5) up to 500 amplicon sequencing variants (ASVs) identified showed different diversity and abundance. Moreover, the bowel inflammation induced by cancer triggered oxidative stress, which correlated with deficient antioxidant machinery (e.g., NADPH-producing enzymes) determined in the GITm cultures from sick individuals in comparison with those from control individuals. Altogether, the data suggested that to preserve the microbial network between bacteria and methanogenic archaea, a complete oxidation of the carbon source may be essential for healthy microbiota. The correlation of 16S rRNA gene metabarcoding between cultures and feces, as well as metabolomic data found in cultures, suggest that INC-07 medium may be a useful tool to understand the metabolism of microbiota under gut conditions.

DOI： 10.3389/fmicb.2022.949272

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Effect of different concentrations of sodium selenite on anaerobic digestion of waste sewage sludge 査読有り国際誌

Roy C.K., Hoshiko Y., Toya S., Maeda T.

Environmental Technology and Innovation 27 2022年08月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

The effect of sodium selenite on anaerobic digestion of waste sewage sludge (WSS) was studied. Interestingly, methane production was enhanced at 2 mg/L and inhibited at 100 mg/L of sodium selenite during the anaerobic digestion of WSS. Hydrolytic activity increased in correlation with increased concentrations of sodium selenite (0 to 100 mg/L). At the acidogenesis stage, acetic acid accumulated at the concentrations more than 25 mg/L of sodium selenite whereas it was consumed for 10 days at the concentration of 2 mg/L of sodium selenite. Also, the concentration of propionic acid decreased and that of butyric acid increased at 100 mg/L of sodium selenite. Although methanogenic activities were totally inhibited at 100 mg/L of sodium selenite, a high hydrogenotrophic methanogenic activity was observed at 2 mg/L of sodium selenite. The abundance of hydrogenotrophic methanogens (Methanospirillum and Methanocorpusculum) increased in the WSS at 2 mg/L of sodium selenite. Moreover, the results of pure-culture experiments using Methanosarcina acetivorans C2A show that the growth promotion or inhibition was observed at 2 mg/L or at 100 mg/L of sodium selenite. In conclusion, sodium selenite has the double-sided effect during the anaerobic digestion of WSS as shown by the results that methane production was promoted at a low concentration and inhibited at a high concentration.

DOI： 10.1016/j.eti.2022.102403

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A simple approach for random genomic insertion–deletions using ambiguous sequences in Escherichia coli 査読有り

Chandra Shekhar, Toshinari Maeda

Journal of Basic Microbiology ( Wiley ) 62 ( 8 ) 948 - 962 2022年08月

Microbial community structures and methanogenic functions in wetland peat soils 査読有り国際誌

Wipoo Prasitwuttisak, Yuki Hoshiko, Toshinari Maeda, Akira Haraguchi, Katsunori Yanagawa

Microbes and Environmentsthis link is disabled ( 日本微生物生態学会報 ) 37 ( 3 ) ME22004 2022年07月

Impact of 5-fluorouracil on anaerobic digestion using sewage sludge 査読有り国際誌

Hoshiko Y., Hirano R., Mustapha N.A., Nguyen P.D.T., Fujie S., Sanchez-Torres V., Maeda T.

Chemosphere 298 2022年07月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

The role of bacterial interaction is vital to control bacterial functions; however, it has not been fully understood in microbial consortia (including anaerobic digestion). In this study, fluorouracil (FU), which is an anticancer agent and a quorum sensing (QS) inhibitor to some of the Gram-negative bacteria was found to inhibit methane production from sewage sludge under anaerobic conditions, as shown in a result where methane production in the presence of FU was eight times lower than the control (sewage sludge without FU). Whereas FU did not influence the hydrolysis process, in the acidogenesis/acetogenesis process, butyrate, and acetate accumulated in samples with FU. Also, in the methanogenesis process, FU remarkably inhibited methane production by acetoclastic methanogens rather than by the hydrogenotrophic ones. This result agreed with the result that growth and methane production of Methanosarcina acetivorans C2A was inhibited in the presence of FU. However, the inhibitory effect of FU was high in the condition that both bacteria and archaea were active. It indicates that FU influences methanogens and bacteria in the process of methane fermentation. The analyses of microbial communities (bacteria and archaea) showed that the abundance ratio of the Firmicutes phyla is high, and hydrogenotrophic methanogens become dominant in the presence of FU. Conversely, the abundance of Spirochaetes significantly decreased under FU. The inhibition of methane production by FU was due to the growth inhibition of methanogenic archaea and the changes in the composition of the bacterial population.

DOI： 10.1016/j.chemosphere.2022.134253

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Effect of sodium tungstate on anaerobic digestion of waste sewage sludge: Enhanced methane production via increased acetoclastic methanogens 査読有り国際誌

Roy C.K., Toya S., Hoshiko Y., Sabidi S., Mustapha N.A., Miyazaki T., Maeda T.

Journal of Environmental Chemical Engineering 10 ( 3 ) 2022年06月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

In this study, the effect of sodium tungstate on anaerobic digestion of waste sewage sludge (WSS) was investigated. Methane production was enhanced by sodium tungstate in a dose-dependent manner. Sodium tungstate did not affect the hydrolysis stage as the same level of protease activity was detected in the WSS sample with or without sodium tungstate. At the acidogenesis stage, the concentration of acetate decreased during the anaerobic digestion of WSS supplemented with sodium tungstate whereas that of isobutyrate increased. The pH of WSS increased in the presence of sodium tungstate, correlating with the result of acetate consumption with time during the anaerobic digestion of WSS. The analyses of methanogenesis via acetoclastic and hydrogenotrophic methanogens indicate that methane production from acetate was high in the WSS with sodium tungstate. In addition, the addition of sodium tungstate to the initial fresh WSS did not enhance methane production from acetate; therefore, sodium tungstate may increase the number of acetoclastic methanogens rather than promote the catalytic reaction related to the methane production. The analyses of archaeal population supported that acetoclastic methanogens (mostly Methanosaeta) increased with time in the WSS with sodium tungstate. In detail, when compared to the control WSS, the percentage of Methanosaeta significantly increased from 3.02% to 31.20% in the presence of sodium tungstate. Furthermore, the addition of sodium tungstate enhanced the growth of Methanosarcina acetivorans C2A. Taken together, sodium tungstate increases methane production via the anaerobic digestion of WSS by increasing the activity of acetoclastic methanogenesis.

DOI： 10.1016/j.jece.2022.107524

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九州工業大学大学院生命体工学研究科における生物工学研究招待有り査読有り

前田憲成

生物工学会誌 ( 公益社団法人日本生物工学会 ) 100 ( 4 ) 210 - 211 2022年04月

Molecular engineering of sensory mechanisms in bacteria for biosensing technologies and novel tools for microbial engineering 査読有り国際誌

Rodolfo Garcia-Contreras, Toshinari Maeda, Bernardo Franco

Frontiers in Bioengineering and Biotechnology ( Frontiers ) 10 894553 2022年04月

Advancement of Metatranscriptomics towards Productive Agriculture and Sustainable Environment: A Review 査読有り

Sharuddin S.S., Ramli N., Yusoff M.Z.M., Muhammad N.A.N., Ho L.S., Maeda T.

International Journal of Molecular Sciences 23 ( 7 ) 2022年04月

担当区分：最終著者記述言語：英語掲載種別：記事・総説・解説・論説等（学術雑誌）

While chemical fertilisers and pesticides indeed enhance agricultural productivity, their excessive usage has been detrimental to environmental health. In addressing this matter, the use of environmental microbiomes has been greatly favoured as a ‘greener’ alternative to these inorganic chemicals’ application. Challenged by a significant proportion of unidentified microbiomes with unknown ecological functions, advanced high throughput metatranscriptomics is prudent to over-come the technological limitations in unfolding the previously undiscovered functional profiles of the beneficial microbiomes. Under this context, this review begins by summarising (1) the evolution of next-generation sequencing and metatranscriptomics in leveraging the microbiome transcriptome profiles through whole gene expression profiling. Next, the current environmental metatranscrip-tomics studies are reviewed, with the discussion centred on (2) the emerging application of the beneficial microbiomes in developing fertile soils and (3) the development of disease-suppressive soils as greener alternatives against biotic stress. As sustainable agriculture focuses not only on crop productivity but also long-term environmental sustainability, the second half of the review highlights the metatranscriptomics’ contribution in (4) revolutionising the pollution monitoring systems via specific bioindicators. Overall, growing knowledge on the complex microbiome functional profiles is imperative to unlock the unlimited potential of agricultural microbiome-based practices, which we believe hold the key to productive agriculture and sustainable environment.

DOI： 10.3390/ijms23073737

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オリゴ乳酸の逆相HPLC分析に対するトリフルオロ酢酸添加の影響査読有り

園田達彦, 吉田雄治, 前田憲成, 水野康平

分析化学 ( 公益社団法人日本分析化学会 ) 71 ( 3 ) 197 - 200 2022年03月

記述言語：日本語掲載種別：記事・総説・解説・論説等（学術雑誌）

With the recent increase in demand for biodegradable plastics triggered by the microplastics problem, the reuse of waste is also attracting attention. For example, VTT Technical Research Centre of Finland holds a patent to produce high-purity oligo(lactic acid) (OLA) from polylactic acid waste. If a new useful strain capable of assimilating the OLA can be discovered, it will be possible to produce useful substances from polylactic acid-based waste. For that purpose, it is necessary to clarify the relationship between bacteria and the OLA. As part of this, we tried to analyze the hydrolysis behavior of oligo(lactic acid) using reverse-phase HPLC. From the results, it was shown that the addition of trifluoroacetic acid (TFA) to the HPLC eluent significantly suppressed the broadening of the peaks derived from the OLA, enabling the quantification of OLA. The analytical method will be useful for investigating the effects of useful bacteria on the OLA.

DOI： 10.2116/bunsekikagaku.71.197

CiNii Research

嫌気消化試料からの核酸抽出におけるタングステン酸ナトリウムの影響－リボ核酸の定量における蛍光度法の有効性－査読有り

遠矢将太郎, 園田達彦, 前田憲成

分析化学 ( 公益社団法人日本分析化学会 ) 71 ( 3 ) 201 - 206 2022年03月

担当区分：最終著者,　責任著者記述言語：日本語掲載種別：研究論文（学術雑誌）

Nucleic acid extracted from environmental samples is an important analyte in instrumental analysis. With respect to the phenomenon in which sodium tungstate promotes the methane production in anaerobic digestion, the analyses of microbial community using RNA were conducted; however, we noticed that only RNA concentration measured by absorbance measurement (NanoDrop) was remarkably high. Therefore, in this study, DNA and RNA were extracted from the anaerobic digestion sludge samples with sodium tungstate, sodium selenite, or sodium molybdate, and these nucleic acids were quantified and compared by absorbance measurement, fluorescence measurement (Qubit), and gel electrophoresis. Interestingly, it was found that only the RNA concentration of the sample containing sodium tungstate measured by NanoDrop was 3 times higher than that by Qubit analysis. In addition, there was no difference between the RNA concentration measured by Qubit and gel electrophoresis. Regarding DNA concentration and the other compounds, there were no differences. Hence, these results indicate that the Qubit system is useful for the quantification of the RNA concentration in the environmental samples.

DOI： 10.2116/bunsekikagaku.71.201

CiNii Research

Cu2O/TiO2 decorated on cellulose nanofiber/reduced graphene hydrogel for enhanced photocatalytic activity and its antibacterial applications 査読有り

Zheng, A.L.T., Sabidi, S., Ohno, T., Maeda, T., Andou, Y.

Chemosphere ( Elsevier ) 286 131731 2022年01月

Accessing the anti-microbial activity of cyclic peptide immobilized on reduced graphene oxide 査読有り

Zheng A.L.T., Farrag H.N., Sabidi S., Kato T., Maeda T., Andou Y.

Materials Letters 304 2021年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

Herein, we prepared and characterized two antimicrobial cyclic peptides immobilized on reduced graphene oxide (rGO) and accessed their anti-bacterial towards Gram-negative (Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus) bacterias. The covalent interaction between the tyrosine and histidine based cyclic peptides and the rGO occurred via the carboxylic groups of the reduced graphene and the amino side chain groups of the cyclic peptides. A selective antibacterial effect is observed for the cyclic peptides functionalized rGO. The inhibition zone test showed that both the tyrosine and histidine cyclic based peptide immobilized on rGO exhibited higher anti-bacterial potency towards the bacteria in comparison to bare rGO which can be attributed to the synergistic effect of the antimicrobial peptide and rGO.

DOI： 10.1016/j.matlet.2021.130621

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Zero-emission of palm oil mill effluent final discharge promoted bacterial biodiversity rebound in the receiving water system 査読有り

Mohamad-Zainal N.S.L., Ramli N., Zolkefli N., Jamari N.A., Mustapha N.A., Hassan M.A., Maeda T.

Applied Sciences (Switzerland) 11 ( 22 ) 2021年11月

記述言語：英語掲載種別：研究論文（学術雑誌）

Zero-emission technology for palm oil mill effluent (POME) has led to a breakthrough in the palm oil industry in relation to the goal of sustainable development. However, there are limited resources on how this technology has affected the bacterial community in the receiving river that has previously been polluted with POME final discharge. Thus, the current study assessed the recoverability of the unexplored bacterial community in the receiving water of a constructed river water system post-zero emission of POME final discharge. An artificial river water system was constructed in this study, where the viability status and the composition of the bacterial community were assessed for 15 days using a flow cytometry-based assay and high-throughput sequencing by Illumina MiSeq, respectively. The zero-emission of POME final discharge reduced not only the physicochemical properties and nutrient contents of the receiving water, but also the bacterial cells’ viability from 40.3% to 24.5% and shifted the high nucleic acid (HNA) to low nucleic acid (LNA) content (38.7% to 34.5%). The proposed POME bacterial indicators, Alcaligenaceae and Chromatiaceae were not detectable in the rainwater (control) but were detected in the artificial river water system after the introduction of POME final discharge at the compositions of 1.0–1.3% and 2.2–5.1%, respectively. The implementation of a zero-emission system decreased the composition of Chromatiaceae from 2.2% on day 8 until it was undetectable on day 15, while Alcaligenaceae was continuously reduced from 1.2% to 0.9% within that similar time frame. As indicated by principal coordinate (PCO) analysis, the reductions in biological oxygen demand (BOD5 ) would further diminish the compositions of these bioindicators. The zero-emission of POME final discharge has demonstrated its efficacy, not only in reducing the polluting properties, but also in the bacterial biodiversity rebound in the affected water system.

DOI： 10.3390/app112210814

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Bioenergy from dairy manure: technologies, challenges and opportunities 査読有り

Zhu Q.L., Wu B., Pisutpaisal N., Wang Y.W., Ma K.d., Dai L.C., Qin H., Tan F.R., Maeda T., Xu Y.s., Hu G.Q., He M.X.

Science of the Total Environment 790 2021年10月

記述言語：英語掲載種別：記事・総説・解説・論説等（学術雑誌）

Dairy manure (DM) is a kind of cheap cellulosic biomass resource which includes lignocellulose and mineral nutrients. Random stacks not only leads damage to the environment, but also results in waste of natural resources. The traditional ways to use DM include returning it to the soil or acting as a fertilizer, which could reduce environmental pollution to some extent. However, the resource utilization rate is not high and socio-economic performance is not utilized. To expand the application of DM, more and more attention has been paid to explore its potential as bioenergy or bio-chemicals production. This article presented a comprehensive review of different types of bioenergy production from DM and provided a general overview for bioenergy production. Importantly, this paper discussed potentials of DM as candidate feedstocks not only for biogas, bioethanol, biohydrogen, microbial fuel cell, lactic acid, and fumaric acid production by microbial technology, but also for bio-oil and biochar production through apyrolysis process. Additionally, the use of manure for replacing freshwater or nutrients for algae cultivation and cellulase production were also discussed. Overall, DM could be a novel suitable material for future biorefinery. Importantly, considerable efforts and further extensive research on overcoming technical bottlenecks like pretreatment, the effective release of fermentable sugars, the absence of robust organisms for fermentation, energy balance, and life cycle assessment should be needed to develop a comprehensive biorefinery model.

DOI： 10.1016/j.scitotenv.2021.148199

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Quinolone Signals Related to Pseudomonas Quinolone Signal-Quorum Sensing Inhibits the Predatory Activity of Bdellovibrio bacteriovorus 査読有り

Hoshiko Y., Nishiyama Y., Moriya T., Kadokami K., López-Jácome L.E., Hirano R., García-Contreras R., Maeda T.

Frontiers in Microbiology 12 2021年09月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

Bdellovibrio bacteriovorus is one of the predatory bacteria; therefore, it can act as a novel “living antibiotic,” unlike the current antibiotics. Here the predation of Escherichia coli by B. bacteriovorus was inhibited in the presence of Pseudomonas aeruginosa. This study investigated whether P. aeruginosa-induced predation inhibition is associated with bacterial quorum sensing (QS). Each las, rhl, or pqs QS mutant in P. aeruginosa was used to check the predatory activity of E. coli cells using B. bacteriovorus. As a result, the predatory activity of B. bacteriovorus increased in a mutant pqs QS system, whereas wild-type PA14 inhibited the predatory activity. Moreover, the addition of 4-hydroxy-2-heptylquinoline (HHQ) or the analog triggered the low predatory activity of B. bacteriovorus and killed B. bacteriovorus cells. Therefore, a defensive action of P. aeruginosa against B. bacteriovorus is activated by the pqs QS system, which produces some quinolone compounds such as HHQ.

DOI： 10.3389/fmicb.2021.722579

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Bacterial resistance against heavy metals in #IPseudomonas aeruginosa#IR RW9 involving hexavalent chromium removal 査読有り

Arisah F.M., Amir A.F., Ramli N., Ariffin H., Maeda T., Hassan M.A., Yusoff M.Z.M.

Sustainability (Switzerland) 13 ( 17 ) 2021年09月

記述言語：英語掲載種別：研究論文（学術雑誌）

Pseudomonas aeruginosa RW9 is a promising candidate for the bioremediation of chromium hexavalent (Cr(VI)) pollution, as it resists a high concentration of up to 60 mg/L of Cr(VI). Leaving cells exposed to Cr(VI) has large bioreduction potential, implying its capacity to extract the ions from the contaminated medium. In this study, the tolerance for and distribution of Cr(VI) were investigated to identify the cells’ adaptation and removal strategies. Micro-characterization analysis was conducted to assess the effect of Cr(VI) on the cells. The cells’ elongation was observed at higher Cr(VI) concentrations, signifying their adaptation to DNA damage caused by Cr(VI) toxicity. Cr(VI) distribution analysis showed that the strain developed a complex mechanism to adapt to Cr(VI), based on surface-bound (0.46 mg/L), intracellularly accumulated (1.24 mg/L) and extracellular sequestration (6.74 mg/L), which accounted for 85% of the removal efficiency. The extracellular sequestration might be attributable to the production of metabolites, in accordance with the fourier-transform infrared spectroscopy (FTIR) spectra and orcinol analysis that confirmed the presence of a glycolipid biosurfactant, a rhamnolipid. Remarkably, the rhamnolipid was slightly induced in the presence of Cr(VI). From the data obtained, it was confirmed that this local strain is well equipped to survive high doses of Cr(VI) and has great potential for application in Cr(VI) bioremediation.

DOI： 10.3390/su13179797

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Ecotoxicological assessment of palm oil mill effluent final discharge by zebrafish (Danio rerio) embryonic assay 査読有り

Hashiguchi Y., Zakaria M.R., Toshinari M., Mohd Yusoff M.Z., Shirai Y., Hassan M.A.

Environmental Pollution 277 2021年05月

記述言語：英語掲載種別：研究論文（学術雑誌）

Most palm oil mills adopted conventional ponding system, including anaerobic, aerobic, facultative and algae ponds, for the treatment of palm oil mill effluent (POME). Only a few mills installed a bio-polishing plant to treat POME further before its final discharge. The present study aims to determine the quality and toxicity levels of POME final discharge from three different mills by using conventional chemical analyses and fish (Danio rerio) embryo toxicity (FET) test. The effluent derived from mill A which installed with a bio-polishing plant had lower values of BOD, COD and TSS at 45 mg/L, 104 mg/L, and 27 mg/L, respectively. Only mill A nearly met the industrial effluent discharge standard for BOD. In FET test, effluent from mill A recorded low lethality and most of the embryos were malformed after hatching (half-maximal effective concentration (EC50) = 20%). The highest toxicity was observed from the effluent of mill B and all embryos were coagulated after 24 h in samples greater than 75% of effluent (38% of half-maximal lethal concentration (LC50) at 96 h). The embryos in the effluent from mill C recorded high mortality after hatching, and the survivors were malformed after 96 h exposure (LC50 = 26%). Elemental analysis of POME final discharge samples showed Cu, Zn, and Fe concentrations were in the range of 0.10–0.32 mg/L, 0.01–0.99 mg/L, and 0.94–4.54 mg/L, respectively and all values were below the effluent permissible discharge limits. However, the present study found these metals inhibited D. rerio embryonic development at 0.12 mg/L of Cu, and 4.9 mg/L of Fe for 96 h-EC50. The present study found that bio-polishing plant installed in mill A effectively removing pollutants especially BOD and the FET test was a useful method to monitor quality and toxicity of the POME final discharge samples.

DOI： 10.1016/j.envpol.2021.116780

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Valorization of biodiesel side stream waste glycerol for rhamnolipids production by Pseudomonas aeruginosa RS6 査読有り

Baskaran S.M., Zakaria M.R., Mukhlis Ahmad Sabri A.S., Mohamed M.S., Wasoh H., Toshinari M., Hassan M.A., Banat I.M.

Environmental Pollution 276 2021年05月

記述言語：英語掲載種別：研究論文（学術雑誌）

Biodiesel side stream waste glycerol was identified as a cheap carbon source for rhamnolipids (RLs) production which at the same time could improve the management of waste. The present study aimed to produce RLs by using Pseudomonas aeruginosa RS6 utilizing waste glycerol as a substrate and to evaluate their physico-chemicals properties. Fermentation conditions such as temperature, initial medium pH, waste glycerol concentration, nitrogen sources and concentrations resulted in different compositions of the mono- and di-RLs produced. The maximum RLs production of 2.73 g/L was obtained when P. aeruginosa RS6 was grown in a basal salt medium supplemented with 1% waste glycerol and 0.2 M sodium nitrate at 35 °C and pH 6.5. At optimal fermentation conditions, the emulsification index (E24) values of cooking oil, diesel oil, benzene, olive oil, petroleum, and kerosene were all above E24=50%. The surface tension reduction obtained from 72.13 mN/m to 29.4–30.4 mN/m was better than the surface activity of some chemical-based surfactants. The RLs produced possessed antimicrobial activities against Gram-negative and Gram-positive bacteria with values ranging from 37% to 77% of growth inhibition when 1 mg/mL of RLs was used. Concentrations of RLs below 1500 μg/mL did not induce phytotoxicity effects on the tested seeds (Vigna radiata) compared to the chemical-based- surfactant, SDS. Furthermore, RLs tested on zebrafish (Danio rerio) embryos only exhibited low acute toxicity with an LC50 value of 72.97 μg/mL at 48 h of exposure suggesting a green and eco-biochemical worthy of future applications to replace chemical-based surfactants. Pseudomonas aeruginosa RS6 shows the ability to consume biodiesel side stream waste glycerol for the production of green biochemicals and less-toxic rhamnolipids.

DOI： 10.1016/j.envpol.2021.116742

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Antibacterial chitosan nanofiber thin films with bacitracin zinc salt 査読有り

Kumamoto K., Maeda T., Hayakawa S., Mustapha N.A.B., Wang M.J., Shirosaki Y.

Polymers 13 ( 7 ) 2021年04月

記述言語：英語掲載種別：研究論文（学術雑誌）

Chitosan nanofiber has a highly uniform structure of 20–50 nm in diameter and shows high dispersibility in water due to its submicron size and high surface-to-volume ratio. The stacked nanofibers film is useful for breathability because it has a gap with a size of several tens of nm or more. However, the chemical bonds between the nanofibers cannot be broken during use. In this study, the thin films were obtained by filtration of chitosan nanofibers and 3-glycidoxypropyltri-methoxysilane (GPTMS) mixture. The addition of GPTMS changed the wettability, mechanical property and stability in water of the thin films. Bacitracin zinc salt (BZ) has been used for the localized dermatological medicines and loaded in the films. BZ interacted electrostatically with the thin films matrix and the release of BZ was controlled by the amount of GPTMS. A higher released amount of BZ showed higher antibacterial effects toward S. aureus. The film was also tested their toxicity by L929 fibroblasts. The release of less than 11.9 μg of BZ showed antibacterial effects, but were not toxic for fibroblast cells.

DOI： 10.3390/polym13071104

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Design, synthesis and antibacterial studies of novel cationic amphipathic cyclic undecapeptides and their linear counterparts against virulent bacterial strains 査読有り

Farrag H.N., Maeda T., Kato T.

Scientia Pharmaceutica 89 ( 1 ) 1 - 11 2021年03月

記述言語：英語掲載種別：研究論文（学術雑誌）

Bacteria have acquired resistance against almost all antibiotics because of the misuse of antibacterial agents and long periods of treatment. Antimicrobial peptides (AMPs) are one of the most encouraging candidates to solve this problem, as they possess high prokaryotic selectivity, and affect the bacteria by a unique mode of action. Novel cyclic undecapeptides (QNRNFYFNRNQ and QNRNFHFNRNQ) and their linear counterparts were investigated for their antibacterial activity against virulent strains. The minimal inhibitory concentration (MIC) values showed that tyrosine and histidine AMPs have promising antibacterial activity against virulent bacteria. The MIC values against the P. aeruginosa PA14, E. coli O157:H7 CR3, S. aureus 209P, and B. subtilis ATCC 6633 bacterial strains were evaluated for the cyclic peptide containing tyrosine, and their values were 6.25, 12.5, 12.5, and 12.5 µM, respectively. Meanwhile, for the linear form, they were 9.3, 12.5, 12.5, and 12.5 µM, respectively. The cyclic-peptide–containing histidines’ MIC values were 6.25, 3.1, 6.25, and 3.1 µM, respectively. Meanwhile, for the linear form, they were 3.1, 3.1, 3.1, and 6.25 µM, respectively. The antibacterial activities of the new AMPs were compared with that of gentamicin sulfate, and showed relatively higher potencies. Time-inhibition studies demonstrated the rapid antibacterial effects of the novel AMPs, which were more likely to be concentration-dependent, rather than time-dependent. At double the MIC concentration, all of the tested peptides exhibited relatively stable antibacterial effects up to 24 h, especially the peptides containing tyrosine, which showed an improved antibacterial effect.

DOI： 10.3390/scipharm89010010

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Enrichment of waste sewage sludge for enhancing methane production from cellulose 査読有り

Zhu Q., Dai L., Wang Y., Tan F., Chen C., He M., Maeda T.

Bioresource Technology 321 2021年02月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

Low ability of waste sewage sludge to degrade cellulose is observed due to its less cellulolytic bacteria content. The enrichment of sewage sludge in the absence or presence of carboxymethylcellulose (CMC) was conducted to improve anaerobic digestion (AD) of cellulose in this study. Compared to initial sewage sludge (IS), enriched sludge without CMC addition (ES) displayed 69.81% higher CH yield and about 1.7-fold greater anaerobic biodegradation of cellulose. In particular, bacterial and archaeal diversities in samples inoculated with ES were significantly altered, with Ruminiclostridium and Methanobacterium as the predominant genera. Enriched sludge with CMC addition (ESC) displayed enhanced methane production at initial cellulose fermentation but showed no distinct difference compared with the control after incubation 24 days. These findings suggest that enrichment of waste sewage sludge without CMC addition is more beneficial for promoting AD of cellulose, providing a novel insight for efficient energy utilization of lignocellulosic wastes. 4

DOI： 10.1016/j.biortech.2020.124497

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Diluted Luria-Bertani medium vs. sewage sludge as growth media: comparison of community structure and diversity in the culturable bacteria 査読有り

Yamamoto K., Toya S., Sabidi S., Hoshiko Y., Maeda T.

Applied Microbiology and Biotechnology 2021年01月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

Because colony formation is essential to seek bacterial functions by the direct observation of phenotype, the diversification of colony formation for culturable bacteria is a big challenge in the research field of Environmental Biotechnology. In this study, the biodiversity of cultivable bacteria (colony or liquid culture) was compared by using Luria-Bertani (LB) medium and waste sewage sludge (WSS) under different dilutions and temperatures. When WSS was used as a bacterial source, whereas the highest number of colonies was found at the concentration of WSS (5%), a particular concentration of LB (10%) or WSS (1%) as a growth medium showed the best number of the operational taxonomic units (OTUs) of colonies. The results of bacterial community structure indicated that there are 1, 8, and 12 bacterial genera found uniquely in the agar plates of LB, 10% LB, and 5% WSS. By contrast, when palm oil mill effluent sludge was used as a bacterial source, the effect of dilution was different with WSS. When comparing the biodiversity between colonies and liquid culture, a high OTU value was observed in the colonies on the plate. In addition, 30°C showed the highest number of colonies in LB, 10% LB, and 5% WSS whereas the best OTUs were observed at 37°C for LB and 10% LB, and at 25°C for 5% WSS. This study demonstrates the diversification of cultivable bacteria through the number of OTUs in diluted LB medium and WSS, which is beneficial to isolate a unique bacterial strain. Key points • Impacts of diluted LB medium and WSS for colony formation were determined. • Difference of concentration of LB and WSS made different effects on colony formation. • Temperature change affected on diluted LB and WSS as media.

DOI： 10.1007/s00253-021-11248-4

Scopus

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Iron limitation by transferrin promotes simultaneous cheating of pyoverdine and exoprotease in Pseudomonas aeruginosa 査読有り

Tostado-Islas O., Mendoza-Ortiz A., Ramírez-García G., Cabrera-Takane I.D., Loarca D., Pérez-González C., Jasso-Chávez R., Jiménez-Cortés J.G., Hoshiko Y., Maeda T., Cazares A., García-Contreras R.

ISME Journal 2021年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

Pseudomonas aeruginosa is a primary bacterial model to study cooperative behaviors because it yields exoproducts such as siderophores and exoproteases that act as public goods and can be exploited by selfish nonproducers behaving as social cheaters. Iron-limited growth medium, mainly casamino acids medium supplemented with transferrin, is typically used to isolate and study nonproducer mutants of the siderophore pyoverdine. However, using a protein as the iron chelator could inadvertently select mutants unable to produce exoproteases, since these enzymes can degrade the transferrin to facilitate iron release. Here we investigated the evolutionary dynamics of pyoverdine and exoprotease production in media in which iron was limited by using either transferrin or a cation chelating resin. We show that concomitant loss of pyoverdine and exoprotease production readily develops in media containing transferrin, whereas only pyoverdine loss emerges in medium treated with the resin. Characterization of exoprotease- and pyoverdine-less mutants revealed loss in motility, different mutations, and large genome deletions (13–33 kb) including Quorum Sensing (lasR, rsal, and lasI) and flagellar genes. Our work shows that using transferrin as an iron chelator imposes simultaneous selective pressure for the loss of pyoverdine and exoprotease production. The unintended effect of transferrin uncovered by our experiments can help to inform the design of similar studies.

DOI： 10.1038/s41396-021-00938-6

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Survivability of Alcaligenaceae and Chromatiaceae as palm oil mill effluent pollution bioindicators under fluctuations of temperature, pH and total suspended solid 査読有り

Mohamad-Zainal N.S.L., Ramli N., Zolkefli N., Mustapha N.A., Hassan M.A., Maeda T.

Journal of Bioscience and Bioengineering 2021年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

Alcaligenaceae and Chromatiaceae were previously reported as the specific pollution bioindicators in the receiving river water contaminated by palm oil mill effluent (POME) final discharge. Considering the inevitable sensitivity of bacteria under environmental stresses, it is crucial to assess the survivability of both bacteria in the fluctuated environmental factors, proving their credibility as POME pollution bioindicators in the environment. In this study, the survivability of Alcaligenaceae and Chromatiaceae from facultative pond, algae (aerobic) pond and final discharge were evaluated under varying sets of temperature (25–40°C), pH (pH 7–9) and low/high total suspended solid (TSS) contents of POME collected during low/high crop seasons of oil palm, respectively. Following treatment, the viability status and compositions of the bacterial community were assessed using flow cytometry-based assay and high-throughput Illumina MiSeq, respectively, in correlation with the changes of physicochemical properties. The changes in temperature, pH and TSS indeed changed the physicochemical properties of POME. The functionality of bacterial cells was also shifted where the viable cells and high nucleic acid contents reduced at elevated levels of temperature and pH but increased at high TSS content. Interestingly, the Alcaligenaceae and Chromatiaceae continuously detected in the samples which accounted for more than 0.5% of relative abundance, with a positive correlation with biological oxygen demand (BOD5) concentration. Therefore, either Alcaligenaceae or Chromatiaceae or both could be regarded as the reliable and specific bacterial indicators to indicate the pollution in river water due to POME final discharge despite the fluctuations in temperature, pH and TSS.

DOI： 10.1016/j.jbiosc.2021.04.014

Scopus

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Preparation of bioactive and antibacterial PMMA-based bone cement by modification with quaternary ammonium and alkoxysilane 査読有り

Wang H., Maeda T., Miyazaki T.

Journal of Biomaterials Applications 2021年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

Bone cement based on poly(methyl methacrylate) (PMMA) powder and methyl methacrylate (MMA) liquid is a very popular biomaterial used for the fixation of artificial joints. However, there is a risk of this cement loosening from bone because of a lack of bone-bonding bioactivity. Apatite formation in the body environment is a prerequisite for cement bioactivity. Additionally, suppression of infection during implantation is required for bone cements to be successfully introduced into the human body. In this study, we modified PMMA cement with γ-methacryloxypropyltrimetoxysilane and calcium acetate to introduce bioactive properties and 2-(tert-butylamino)ethyl methacrylate (TBAEMA) to provide antibacterial properties. The long-term antibacterial activity is attributed to the copolymerization of TBAEMA and MMA. As the TBAEMA content increased, the setting time increased and the compressive strength decreased. After soaking in simulated body fluid, an apatite layer was detected within 7 days, irrespective of the TBAEMA content. The cement showed better antibacterial activity against Gram-negative E. Coli than Gram-positive bacteria; however, of the Gram-positive bacteria investigated, B. subtilis was more susceptible than S. aureus.

DOI： 10.1177/08853282211004413

Scopus

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Antibacterial properties of phenothiazine derivatives against multidrug-resistant Acinetobacter baumannii strains 査読有り

Aguilar-Vega L., López-Jácome L.E., Franco B., Muñoz-Carranza S., Vargas-Maya N., Franco-Cendejas R., Hernández-Durán M., Otero-Zúñiga M., Campo-Beleño C., Jiménez-Cortés J.G., Martínez-Vázquez M., Rodríguez-Zavala J.S., Maeda T., Zurabian R., García-Contreras R.

Journal of Applied Microbiology 2021年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

Aim: As options to treat recalcitrant bacterial infections which are increasingly limited due to multidrug-resistant strains, searching for new, effective antibacterial compounds is necessary. One strategy is to generate treatment alternatives by drug repurposing. Methods and Results: In this work, phenotypic microarrays were used for the screening of miscellaneous compounds against the growth and biofilm formation of Acinetobacter baumannii, an important emergent multidrug-resistant opportunistic pathogen. The results showed that the phenothiazine derivatives, such as promethazine, trifluoperazine, thioridazine, and chlorpromazine, inhibited the growth of antibiotic-sensitive and multidrug-resistant strains (showing minimal inhibitory concentrations ranging from 0·05 to 0·6 g l−1 and minimal bactericidal concentrations ranging from 0·1 to 2·5 g l−1). All phenothiazine derivatives were active against biofilm cells (with minimal biofilm eradication concentrations ranging from 0·5 to >3 g l−1). Chlorpromazine promoted reactive oxigen species (ROS) production, and cell membrane and DNA damage. Chlorpromazine showed synergy with antibiotics such as ceftazidime, meropenem, and colistin and was an effective treatment for experimentally infected Galleria mellonella when combined with ceftazidime. Conclusions: It was demonstrated that phenothiazine derivatives, especially chlorpromazine, are drugs with attractive antibacterial properties against nosocomial MDR strains of A. baumannii, by generating ROS and cell membrane and DNA damage. Significance and Impact of the Study: The present study indicates that repurposing phenothiazine derivatives for treating recalcitrant infections by A. baumannii could be promising.

DOI： 10.1111/jam.15109

Scopus

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Microbial community dynamics and electricity generation in MFCs inoculated with POME sludges and pure electrogenic culture 査読有り

Albarracin-Arias J.A., Yu C.P., Maeda T., Valdivieso Quintero W., Sanchez-Torres V.

International Journal of Hydrogen Energy 2021年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

Palm Oil Mill Effluent (POME) requires treatment before disposal due to its high organic matter content. In this study, the electrical performance and wastewater treatment efficiency were evaluated for Microbial Fuel Cells (MFC) treating unsterile POME with chemical oxygen demand (COD) from 200 to 10 000 mg/L. Since the inoculum type is a key factor in MFC performance, three types of sludge (methanogenic sludge (MS), facultative sludge (FS), and dry sludge (DS), obtained from the current POME treatment ponds were evaluated as inoculum. Dry sludge (DS) developed a maximum power output of 3.30 W/m3 by oxidizing 71% out of the COD provided by POME (1000 mg/L). Also, raw POME microbiota contributed to an enrichment of the community in DS inoculum along with the operation, in which Geobacter was the predominant genus reaching a current generation of 247 mA/m2 and a power density of 2.36 W/m3. Conversely, pure electrogenic (Shewanella sp.) inoculation led to a diversification process, resulting in a lower current generation of 52 mA/m2 and a power density of 0.10 W/m3. Consequently, microbial community dynamics revealed that MFC inoculation tends to a microbial equilibrium wherein generation of high current density was achieved by gradual microbial enrichment rather than external electrogenic invasion.

DOI： 10.1016/j.ijhydene.2021.08.218

Scopus

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Engineering anaerobic digestion via optimizing microbial community: effects of bactericidal agents, quorum sensing inhibitors, and inorganic materials 招待有り査読有り

Maeda T., Sabidi S., Sanchez-Torres V., Hoshiko Y., Toya S.

Applied Microbiology and Biotechnology 2021年01月

担当区分：筆頭著者記述言語：英語掲載種別：記事・総説・解説・論説等（学術雑誌）

Abstract: Anaerobic digestion of sewage sludge (SS) is one of the effective ways to reduce the waste generated from human life activities. To date, there are many reports to improve or repress methane production during the anaerobic digestion of SS. In the anaerobic digestion process, many microorganisms work positively or negatively, and as a result of their microbe-to-microbe interaction and regulation, methane production increases or decreases. In other words, understanding the complex control mechanism among the microorganisms and identifying the strains that are key to increase or decrease methane production are important for promoting the advanced production of bioenergy and beneficial compounds. In this mini-review, the literature on methane production in anaerobic digestion has been summarized based on the results of antibiotic addition, quorum sensing control, and inorganic substance addition. By optimizing the activity of microbial groups in SS, methane or acetate can be highly produced. Key points: • Bactericidal agents such as an antibiotic alter microbial community for enhanced CH4production. • Bacterial interaction via quorum sensing is one of the key points for biofilm and methane production. • Anaerobic digestion can be altered in the presence of several inorganic materials.

DOI： 10.1007/s00253-021-11536-z

Scopus

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下水汚泥の嫌気消化促進のための微生物相互作用の理解招待有り査読有り

前田憲成

生物工学会誌 ( 公益社団法人日本生物工学会 ) 99 ( 12 ) 621 - 622 2021年01月

A Novel Archaeal Lineage in Boiling Hot Springs around Oyasukyo Gorge (Akita, Japan) 査読有り

Asamatsu Katsuhiro, Yoshitake Kai, Saito Makoto, Prasitwuttisak Wipoo, Ishibashi Jun-ichiro, Tsutsumi Akihi, Mustapha Nurul Asyifah, Maeda Toshinari, Yanagawa Katsunori

Ｍｉｃｒｏｂｅｓ　ａｎｄ　ｅｎｖｉｒｏｎｍｅｎｔｓ ( 日本微生物生態学会 / 日本土壌微生物学会 / Taiwan Society of Microbial Ecology / 植物微生物研究会 / 極限環境微生物学会 ) 36 ( 4 ) 2021年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

A novel deep-branching archaeal lineage was discovered at high-temperature hot springs around Oyasukyo Gorge in Akita Prefecture, Japan. Actively boiling hot spring water contained >1×104 microbes mL–1. The microbial community composition assessed by analyzing 16S rRNA gene amplicons revealed that the dominant bacterial phyla were Proteobacteria and Aquificae (>50% of the microbial composition) in samples collected in 2016 and 2019, respectively. Approximately 10% of the reads obtained in both years were not assigned to any taxonomy. The more detailed phylogenetic positions of the unassigned sequences identified using a clone library and phylogenetic tree showed that they formed a clade that was independent, distantly related to known phyla, and had low similarity (<82%) to all other sequences in available databases. The present results suggest that this novel archaeal phylum-level lineage thrives in boiling hot springs in Japan.

DOI： 10.1264/jsme2.ME21048

CiNii Article

その他リンク： https://ci.nii.ac.jp/naid/130008120278

Effect of Aso limonite on anaerobic digestion of waste sewage sludge 査読有り

Mustapha N.A., Toya S., Maeda T.

AMB Express 10 ( 1 ) 2020年12月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2020, The Author(s). The effect of Aso volcanic limonite was explored in anaerobic digestion using waste sewage sludge (WSS). In this study, methane and hydrogen sulfide were remarkably inhibited when Aso limonite was mixed with WSS as well as a significant reduction of ammonia. Although pH was lowered after adding Aso limonite, methane was still inhibited in neutralized pH condition at 7.0. Hydrolysis stage was not influenced by Aso limonite as supported by the result that a high protease activity was still detected in the presence of the material. However, acidogenesis stage was affected by Aso limonite as indicated by the different productions of organic acids. Acetic acid, was accumulated in the presence of Aso limonite due to the inhibition of methane production, except in the highest concentration of Aso limonite which the production of acetate may be inhibited. Besides, the production of propionate and butyrate reduced in accordance to the increased concentration of Aso limonite. In addition, Archaeal activity (methanogens) in WSS with Aso limonite was low in agreement with the low methane production. Thus, these results indicate that Aso limonite influences the acidogenesis and methanogenesis processes, by which the productions of methane and ammonia were inhibited. On the other hand, in the contactless of Aso limonite during the anaerobic digestion of WSS (Aso limonite was placed in the area of headspace in the vial), Aso limonite had the adsorptive ability for hydrogen sulfide from WSS, but not for methane. This contactless system of Aso limonite may be a practical means to remove hydrogen sulfide without inhibiting methane production as an important bioenergy source.

DOI： 10.1186/s13568-020-01010-w

Kyutacar

Scopus

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A review of current and emerging approaches for water pollution monitoring 査読有り

Zolkefli N., Sharuddin S.S., Yusoff M.Z.M., Hassan M.A., Maeda T., Ramli N.

Water (Switzerland) 12 ( 12 ) 1 - 30 2020年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. The aquatic ecosystem is continuously threatened by the infiltration and discharge of anthropogenic wastewaters. This issue requires the unending improvement of monitoring systems to become more comprehensive and specific to targeted pollutants. This review intended to elucidate the overall aspects explored by researchers in developing better water pollution monitoring tools in recent years. The discussion is encircled around three main elements that have been extensively used as the basis for the development of monitoring methods, namely the dissolved compounds, bacterial indicator, and nucleic acids. The latest technologies applied in wastewater and surface water mapped from these key players were reviewed and categorized into physicochemical and compound characterizations, biomonitoring, and molecular approaches in taxonomical and functional analyses. Overall, researchers are continuously rallying to enhance the detection of causal source for water pollution through either conventional or mostly advanced approaches focusing on spectrometry, high-throughput sequencing, and flow cytometry technology among others. From this review’s perspective, each pollution evaluation technology has its own advantages and it would be beneficial for several aspects of pollutants assessments to be combined and established as a complementary package for better aquatic environmental management in the long run.

DOI： 10.3390/w12123417

Scopus

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Effect of calcium acetate content on apatite-forming ability and mechanical property of pmma bone cement modified with quaternary ammonium 査読有り

Wang H., Maeda T., Miyazaki T.

Materials 13 ( 21 ) 1 - 8 2020年11月

記述言語：英語掲載種別：研究論文（学術雑誌）

© MDPI AG. All rights reserved. Polymethyl methacrylate (PMMA)-based bone cement is a popular biomaterial used for fixation of artificial joints. A next-generation bone cement having bone-bonding ability, i.e., bioactivity and antibacterial property is desired. We previously revealed that PMMA cement added with 2-(tert-butylamino)ethyl methacrylate, γ-methacryloxypropyltrimethoxysilane and calcium acetate showed in vitro bioactivity and antibacterial activity. This cement contains calcium acetate at 20% of the powder component. Lower content of the calcium acetate is preferable, because the release of a lot of calcium salt may degrade mechanical properties in the body environment. In the present study, we investigate the effects of calcium acetate content on the setting property and mechanical strength of the cement and apatite formation in simulated body fluid (SBF). The setting time increased and the compressive strength decreased with an increase in calcium acetate content. Although the compressive strength decreased after immersion in SBF for 7 d, all the cements still satisfied the requirements of ISO5833. Apatite was formed in SBF within 7 d on the samples where the calcium acetate content was 5% or more. Therefore, it was found that PMMA cement having antibacterial properties and bioactivity can be obtained even if the amount of the calcium acetate is reduced to 5%.

DOI： 10.3390/ma13214998

Scopus

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Mechanism of carbon partitioning towards starch and triacylglycerol in Chlorella vulgaris under nitrogen stress through whole-transcriptome analysis 査読有り

Nordin N., Yusof N., Maeda T., Mustapha N.A., Mohd Yusoff M.Z., Raja Khairuddin R.F.

Biomass and Bioenergy 138 2020年07月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2020 Elsevier Ltd This study aims to elucidate the mechanism of carbon partitioning towards starch and triacylglycerol (TAG) under nitrogen stress. Whole-transcriptome analysis was performed using RNA sequencing before being validated with qRT-PCR. The strain, Chlorella vulgaris UPSI-JRM01, exhibited a two-stage response to nitrogen stress: i) carbohydrate accumulation, plastid protein degradation and amino acid biosynthesis; and ii) lipid accumulation, carbohydrate degradation and DNA damage. In the first stage, the genes responsible for plastid protein degradation (CD4A), amino acid biosynthesis (arg, GLSN, AHCY, win1), carbon fixation (RuBisCO, GapC, fba, TK) and starch synthesis (SS, SBE2) were upregulated. In the second stage, the upregulation of genes responsible for starch degradation (SP), glycolysis (PFO, PK, ACS), fatty acid biosynthesis (FabH, accD) and TAG accumulation (DGAT2) were observed. By contrast, the components of photosystem I (PsbD, PsbC, PsbB), photosystem II (PsaA), cytochrome b6/f (PetA, PetG) and F-type ATPase (beta, alpha) were downregulated. The results suggested that nitrogen stress triggered high starch accumulation before the carbon was partitioned towards triacylglycerol (TAG) for long-term energy storage by two different pathways: chloroplastic TAG synthesis and glycerolipid metabolism. The starch build-up functions served as a rapid response to nitrogen stress, whereas subsequent lipid accumulation benefited the long-term storage of energy. This research provides in-depth understanding of the metabolic changes triggered by nitrogen stress.

DOI： 10.1016/j.biombioe.2020.105600

Scopus

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Microalgae-bacteria interaction in palm oil mill effluent treatment 査読有り

Mohd Udaiyappan A.F., Hasan H.A., Takriff M.S., Abdullah S.R.S., Maeda T., Mustapha N.A., Mohd Yasin N.H., Nazashida Mohd Hakimi N.I.

Journal of Water Process Engineering 35 2020年06月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2020 Elsevier Ltd Palm oil mill effluent (POME) contains a substantial amount of nutrients and a significant amount of indigenous microorganisms that consume the nutrients for their growth. In this study, we demonstrated that cultivation of microalgae in POME was able to reduce its carbon and nutrient contents. Three native microalgae isolates, namely, Coelastrella sp. UKM4, Chlamydomonas sp. UKM6 and Scenedesmus sp. UKM9, were cultured in sterilized and unsterilized anaerobic POME to evaluate the microalgae-bacteria interactions for phycoremediation of POME. The results showed higher COD removal in unsterilized POME than in sterilized POME due to microalgae-bacteria consortia interaction. Of the three microalgae isolates, the interaction of Scenedesmus sp. UKM9 with bacteria showed the highest COD and PO43− removal percentages. For NH4+ removal, all three isolates showed removal of more than 80 % in both sterilized and unsterilized POME. Quantitative real-time polymerase chain reaction analysis showed that the quantities of bacteria were constant after the treatment, while the quantities of microalgae changed. Metagenomics analysis showed that the community of bacteria shifted after microalgae cultivation in POME, with Actinobacteria, Bacteroidetes, Planctomycetes and Proteobacteria being the major phyla.

DOI： 10.1016/j.jwpe.2020.101203

Scopus

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Characterization of gallium resistance induced in a Pseudomonas aeruginosa cystic fibrosis isolate 査読有り

Tovar-García A., Angarita-Zapata V., Cazares A., Jasso-Chávez R., Belmont-Díaz J., Sanchez-Torres V., López-Jacome L.E., Coria-Jiménez R., Maeda T., García-Contreras R.

Archives of Microbiology 202 ( 3 ) 617 - 622 2020年04月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019, Springer-Verlag GmbH Germany, part of Springer Nature. The repurposing of gallium nitrate as an antibacterial, a drug used previously for the treatment of hypercalcemia, is a plausible alternative to combat infections by Pseudomonas aeruginosa, since it has antipseudomonal properties in vitro and in vivo in animal models and in human lung infections. Furthermore, gallium nitrate tolerance in clinical isolates is very rare. Nevertheless, studies on the reference strains PA14 and PAO1 show that resistance against gallium nitrate is achieved by decreasing gallium intracellular levels by increasing the production of pyocyanin. In this work, we induced resistance in a cystic fibrosis P. aeruginosa isolate and explored its resistance mechanisms. This isolated strain, INP-58M, was not a pyocyanin producer, and its pyoverdine levels remained unchanged upon gallium addition. However, it showed higher activities of NADPH-producing enzymes and the antioxidant enzyme SOD when gallium was added, which suggests a better antioxidant response. Remarkably, gallium intracellular levels in the resistant isolate were higher than those of the parental strain at 20 h but lower after 24 h of culture, suggesting that this strain is capable of gallium efflux.

DOI： 10.1007/s00203-019-01777-y

Scopus

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Biochar enhanced the nitrifying and denitrifying bacterial communities during the composting of poultry manure and rice straw 査読有り

Zainudin M.H., Mustapha N.A., Maeda T., Ramli N., Sakai K., Hassan M.

Waste Management 106 240 - 249 2020年04月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2020 Elsevier Ltd Biochar has proven to be a feasible additive for mitigating nitrogen loss during the composting process. This study aims to evaluate the influence of biochar addition on bacterial community and physicochemical properties changes, including ammonium (NH4+), nitrite (NO2−) and nitrate (NO3−) contents during the composting of poultry manure. The composting was carried out by adding 20% (w/w) of biochar into the mixture of poultry manure and rice straw with a ratio of 2:1, and the same treatment without biochar was prepared as a control. The finished product of control compost recorded the high contents of NO2− and NO3− (366 mg/kg and 600 mg/kg) with reduced the total NH4+ content to 10 mg/kg. Meanwhile, biochar compost recorded a higher amount of total NH4+ content (110 mg/kg) with low NO2− and NO3− (161 mg/kg and 137 mg/kg) content in the final composting material. The principal component analysis showed that the dynamics of dominant genera related to Halomonas, Pusillimonas, and Pseudofulvimonas, all of which were known as nitrifying and denitrifying bacteria, was significantly correlated with the dynamic of NO2− and NO3− content throughout the composting process. The genera related to Pusillimonas, and Pseudofulvimonas appeared as the dominant communities as the NO2− and NO3− increased. In contrast, as the NO2− and NO3− concentration decreased, the Halomonas genus were notably enriched in biochar compost. This study revealed the bacterial community shifts corresponded with the change of physicochemical properties, which provides essential information for a better understanding of monitoring and improving the composting process.

DOI： 10.1016/j.wasman.2020.03.029

Scopus

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Alcaligenaceae and Chromatiaceae as pollution bacterial bioindicators in palm oil mill effluent (POME) final discharge polluted rivers 査読有り

Zolkefli N., Ramli N., Mohamad-Zainal N., Mustapha N., Yusoff M., Hassan M., Maeda T.

Ecological Indicators 111 2020年04月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019 Elsevier Ltd Microorganisms are progressively adopted as reliable and specific bioindicators of pollution, with Alcaligenaceae and Chromatiaceae being recently proposed to indicate contamination in river water due to palm oil mill effluent (POME) final discharge. This study was conducted to evaluate the reliability of these bacteria to act as specific bioindicators by assessing their detections in correlation with environmental factors in rivers polluted by POME final discharge when compared to by other pollution sources. By using the Illumina MiSeq high throughput sequencing platform, bacterial diversities and compositions were compared among unpolluted (upstream) river, polluted rivers due to POME final discharge and other rivers polluted by mining, chemical and automotive industries. To correlate between bacterial compositions and metabolisms in rivers subjected to different pollutants sources, the viability and the ratio of the high and low nucleic acids (HNA/LNA) bacterial cells were also compared by using a double staining assay based on flow cytometry. Interestingly, Alcaligenaceae and Chromatiaceae were found only in POME final discharge polluted rivers (>0.15%) but were not detected in rivers polluted by other pollutants. Higher bacterial cell viability was detected in rivers polluted by POME final discharge (86–91%) as compared to the other polluted rivers (15–80%). From the viable fractions of the bacterial cells, higher HNA cells (91–93%) were quantified in the POME final discharge receiving rivers but with only 5–18% in the other rivers. These trends indicated that the nutrients carried by the POME final discharge enhanced the growth of bacteria in the receiving river water that might include Alcaligenaceae and Chromatiaceae. These results suggested that either Alcaligenaceae or Chromatiaceae or both were unique in the POME final discharge polluted rivers but not in the others. They could function as specific and reliable bacterial bioindicators relevant for the establishment of a complementary monitoring system for POME pollutant discharge.

DOI： 10.1016/j.ecolind.2019.106048

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Toxicity identification and evaluation of palm oil mill effluent and its effects on the planktonic crustacean Daphnia magna 査読有り

Hashiguchi Y., Zakaria M.R., Maeda T., Yusoff M.Z.M., Hassan M.A., Shirai Y.

Science of the Total Environment 710 2020年03月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019 Elsevier B.V. Palm oil mill effluent (POME) contains complex and highly biodegradable organic matters so discharging it without appropriate treatment may lead to environmental problems. POME final discharge quality is normally determined based on conventional chemical detection such as by biological oxygen demand (BOD) and chemical oxygen demand (COD). The novelty of the present study is that the toxicity effects of the POME final discharge samples were evaluated based on whole effluent toxicity (WET) and toxicity identification evaluation (TIE) tests using Daphnia magna. The toxicity unit (TU) values were recorded to be in the range from TU = 1.1–11 obtained from WET, and the TIE manipulation tests suggested that a substantial amount of toxic compounds was contained in the POME final discharge. Phenol, 2,6-bis (1,1-dimethylethyl)- and heavy metals such as Cu and Zn were detected in all the effluents and were recognized as being the main toxicants in the POME final discharge. GC/MS analyses also successfully identified cyclic volatile methyl siloxanes; cyclotetrasiloxane, octamethyl- (D4), cyclopentasiloxane, decamethyl- (D5), cyclohexasiloxane, dodecamethyl- (D6). D4 was detected at 0.0148–0.0357 mg/L, which could be potentially toxic. The palm oil industry used only water in the form of steam to process the fruits, and the presence of these compounds might be derived from the detergents and grease used in palm oil mill cleaning and maintenance operations. An appropriate treatment process is thus required to eliminate these toxicants from the POME final discharge. It is recommended that two approaches, chemical-based monitoring as well as biological toxicity-based monitoring, should be utilized for achieving an acceptable quality of POME final discharge in the future.

DOI： 10.1016/j.scitotenv.2019.136277

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Evaluation of hydrogen metabolism by Escherichia coli strains possessing only a single hydrogenase in the genome 査読有り

Shekhar C., Kai T., Garcia-Contreras R., Sanchez-Torres V., Maeda T.

International Journal of Hydrogen Energy 2020年01月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2020 Hydrogen Energy Publications LLC The four hydrogenase isozymes; hydrogenase 1 (Hyd-1), hydrogenase 2 (Hyd-2), hydrogenase 3 (Hyd-3) and hydrogenase 4 (Hyd-4) of Escherichia coli have been reported for their crucial functions in the hydrogen metabolism; however, their distinctive roles could not be completely understood. In this study, four ideal hydrogenase operon mutants, Δhyb hyc hyf, Δhya hyc hyf, Δhya hyb hyf, and Δhya hyb hyc, in which only a single hydrogenase is intact in the genome, were constructed as well as one quadruple mutant (Δhya hyb hyc hyf) that all four hydrogenase operons were deleted. First, single operon mutants and single-gene mutants for each hydrogenase showed different hydrogen productivity and growth in the anaerobic fermentation, indicating that bacterial phenotype regarding the hydrogen metabolism via the deletion of each operon is different with that of each single gene. Then, 4 triple hydrogenase operon mutants and one quadruple mutant were investigated to evaluate the hydrogen metabolism (hydrogen production and uptake) using glucose or glycerol as a substrate of hydrogen fermentation. With both the carbon sources, only Hyd-2 and Hyd-3 were able to produce hydrogen. Furthermore, all the hydrogenases showed hydrogen uptake activity. In addition, no hydrogen production and hydrogen uptake were detected in the quadruple mutant which does not have all 4 hydrogenases. Hydrogen production from Hyd-2 and Hyd-3 was further confirmed by complementing their operons in the cloning vector pBR322.

DOI： 10.1016/j.ijhydene.2020.10.070

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市販味噌に混入させた大腸菌O157の消長査読有り

細谷幸恵, 川崎晋, 前田憲成, 稲津康弘

日本食品科学工学会誌 ( 公益社団法人日本食品科学工学会 ) 67 ( 10 ) 376 - 383 2020年01月

記述言語：日本語掲載種別：研究論文（学術雑誌）

味噌に混入させた大腸菌O157の消長を明らかにするために，市販味噌24検体を対象に複数の保存試験区（5，10，20，30 °C）における大腸菌O157生菌数の変動を寒天平板法およびMPN法により観察した．全保存試験区において，味噌混入下の大腸菌O157は増殖することなく段階的に死滅し，その死滅速度と味噌原料（米，麦，大豆）に関連は見られなかった．一方，味噌検体の水分活性値が大腸菌O157の死滅速度に影響を与える可能性を示した．本結果により，大腸菌O157が意図せず味噌に混入した場合であっても，常温での流通，保存の期間に死滅することから，そのリスクは実質的に無視しうるものであると推察された．

DOI： 10.3136/nskkk.67.376

CiNii Article

その他リンク： https://ci.nii.ac.jp/naid/130007934533

Fate of Escherichia coli O157 spiked into commercially available fermented soybean paste (MISO) 査読有り

Hosotani Y., Kawasaki S., Maeda T., Inatsu Y.

Nippon Shokuhin Kagaku Kogaku Kaishi 67 ( 10 ) 376 - 383 2020年01月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Copyright© 2020, Japanese Society for Food Science and Technology This study investigated the fate of Escherichia coli (E. coli) O157 spiked into 24 commercially available fermented soybean paste (miso) samples. Viable cell numbers of the inoculated E. coli O157 at storage conditions of 5, 10, 20, or 30 ℃ were measured by the agar plate method or most probable number method. Cell numbers of E. coli O157 decreased gradually in all tested samples. The decreases in E. coli O157 numbers depended mainly on the water activity of samples. Decreases in the contamination level of E. coli O157 did not depend on the ingredients of miso samples (malted rice, wheat, and soybean). The obtained results suggest that the commercial risk of accidental E. coli O157 contamination is practically negligible because of high cell mortality during transportation and storage processes at room temperature.

DOI： 10.3136/NSKKK.67.376

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Dark fermentative biohydrogen production from palm oil mill effluent: Operation factors and future progress of biohydrogen energy 査読有り

Rosman F.S., Yusoff M.Z.M., Zakaria M.R., Maeda T., Hassan M.A.

Pertanika Journal of Science and Technology 28 ( Special issue 2 ) 243 - 258 2020年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

Malaysia is one of the largest producers and exporters of palm oil, thus, a large amount of palm oil mill effluent (POME) is generated through this process. POME contributes to environmental pollution if it is not properly treated. This complex effluent consists of colloidal matters and mainly organic components with more than 90% water. Thus, it is useful to be used as a substrate for fermentative processes, including biohydrogen production. Biohydrogen from POME is a renewable source that can potentially serve as an alternative to substitute fossil fuels. The abundance of POME and the rising price of fossil fuels in the global market create a demand for this source of energy. However, the complexity of the substituents in POME makes the optimisation of this effluent as a substrate in dark fermentation a challenge. This review article explores the important parameters that need to be considered for optimal biohydrogen production, such as the bioreactor operational parameters and the microbial consortium. Besides, the potential of metabolic engineering as a tool to overcome the limitations of the microbial strains to metabolise POME for increased biohydrogen production was also reviewed. However, further research and development are needed to increase the biohydrogen yield on par with commercial demand.

DOI： 10.47836/pjst.28.S2.19

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AiiM Lactonase Strongly Reduces Quorum Sensing Controlled Virulence Factors in Clinical Strains of Pseudomonas aeruginosa Isolated From Burned Patients 査読有り

López-Jácome L.E., Garza-Ramos G., Hernández-Durán M., Franco-Cendejas R., Loarca D., Romero-Martínez D., Nguyen P.T.D., Maeda T., González-Pedrajo B., Díaz-Guerrero M., Sánchez-Reyes J.L., Díaz-Ramírez D., García-Contreras R.

Frontiers in Microbiology 10 2019年11月

記述言語：英語掲載種別：研究論文（学術雑誌）

© Copyright © 2019 López-Jácome, Garza-Ramos, Hernández-Durán, Franco-Cendejas, Loarca, Romero-Martínez, Nguyen, Maeda, González-Pedrajo, Díaz-Guerrero, Sánchez-Reyes, Díaz-Ramírez and García-Contreras. Pseudomonas aeruginosa is an opportunistic bacterium associated with healthcare infections in intensive care units (ICUs), ventilator-associated pneumonia (VAP), surgical site infections, and burns. This bacterium causes 75% of death in burned patients, since it can develop a persistent biofilm associated with infections, express several virulence factors, and antibiotic-resistance mechanisms. Some of these virulence factors are proteases such as elastase and alkaline protease, or toxic metabolites such as pyocyanin and is one of the few microorganisms able to produce cyanide, which inhibits the cytochrome oxidase of host cells. These virulence factors are controlled by quorum sensing (QS). In this work, 30 P. aeruginosa clinical strains isolated from burned patients from a tertiary hospital in Mexico City were studied. Antibiotic susceptibility tests were done, and virulence factors (elastase, alkaline protease, HCN, and pyocyanin) were determined in presence of an N-acylhomoserine lactonase, AiiM able to hydrolyze a wide range of acyl homoserine lactones. The treatment reduced significantly the activities of elastase and alkaline protease, and the production of pyocyanin and HCN in all producer strains but not the secretion of toxins through the type III secretion system. Our work suggests that AiiM treatment may be an effective therapy to combat P. aeruginosa infection in burn patients.

DOI： 10.3389/fmicb.2019.02657

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Endolithic microbial habitats hosted in carbonate nodules currently forming within sediment at a high methane flux site in the sea of Japan 査読有り

Yanagawa K., Shiraishi F., Tanigawa Y., Maeda T., Mustapha N., Owari S., Tomaru H., Matsumoto R., Kano A.

Geosciences (Switzerland) 9 ( 11 ) 2019年11月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. Concretionary carbonates in deep-sea methane seep fields are formed as a result of microbial methane degradation, called anaerobic oxidation of methane (AOM). Recently, active microorganisms, including anaerobic methanotrophic archaea, were discovered from methane seep-associated carbonate outcroppings on the seafloor. However sedimentary buried carbonate nodules are a hitherto unknown microbial habitat. In this study, we investigated the microbial community structures in two carbonate nodules collected from a high methane flux site in a gas hydrate field off the Oki islands in the Sea of Japan. The nodules were formed around sulfate-methane interfaces (SMI) corresponding to 0.7 and 2.2 m below the seafloor. Based on a geochemical analysis, light carbon isotopic values ranging from -54.91% to -37.32% were found from the nodules collected at the shallow SMI depth, which were attributed to the high contributions of AOM-induced carbonate precipitation. Signatures of methanotrophic archaeal populations within the sedimentary buried nodule were detected based on microbial community composition analyses and quantitative real-time PCR targeted 16S rRNA, and functional genes for AOM. These results suggest that the buried carbonate nodule currently develops AOM-related microbial communities, and grows depending on the continued AOM under high methane flux conditions.

DOI： 10.3390/geosciences9110463

Kyutacar

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Seeding Public Goods Is Essential for Maintaining Cooperation in Pseudomonas aeruginosa 査読有り

Loarca D., Díaz D., Quezada H., Guzmán-Ortiz A., Rebollar-Ruiz A., Presas A., Ramírez-Peris J., Franco-Cendejas R., Maeda T., Wood T., García-Contreras R.

Frontiers in Microbiology 10 2019年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

© Copyright © 2019 Loarca, Díaz, Quezada, Guzmán-Ortiz, Rebollar-Ruiz, Presas, Ramírez-Peris, Franco-Cendejas, Maeda, Wood and García-Contreras. Quorum sensing in Pseudomonas aeruginosa controls the production of costly public goods such as exoproteases. This cooperative behavior is susceptible to social cheating by mutants that do not invest in the exoprotease production but assimilate the amino acids and peptides derived by the hydrolysis of proteins in the extracellular media. In sequential cultures with protein as the sole carbon source, these social cheaters are readily selected and often reach equilibrium with the exoprotease producers. Nevertheless, an excess of cheaters causes the collapse of population growth. In this work, using the reference strain PA14 and a clinical isolate from a burn patient, we demonstrate that the initial amount of public goods (exoprotease) that comes with the inoculum in each sequential culture is essential for maintaining population growth and that eliminating the exoprotease in the inoculum leads to rapid population collapse. Therefore, our results suggest that sequential washes should be combined with public good inhibitors to more effectively combat P. aeruginosa infections.

DOI： 10.3389/fmicb.2019.02322

Kyutacar

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Cytocompatible and antibacterial properties of chitosan-siloxane hybrid spheres 査読有り

Shirosaki Y., Nakatsukasa M., Yasutomi S., Cruz-Neves S., Hayakawa S., Osaka A., Maeda T., Miyazaki T.

Polymers 11 ( 10 ) 2019年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. Microporous spheres in a hybrid system consisting of chitosan and γ-glycidoxypropyltrimethoxysilane (GPTMS) have advantages in a range of applications, e.g., as vehicles for cell transplantation and soft tissue defect filling materials, because of their excellent cytocompatibility with various cells. In this study, microporous chitosan-GPTMS spheres were prepared by dropping chitosan-GPTMS precursor sols,with orwithout a ceriumchloride, into liquid nitrogen using a syringe pump. The droplets were then freeze dried to give the pores of size 10 to 50 μm. The cell culture tests showed that L929 fibroblast-like cells migrated into the micropores larger than 50 μm in diameter, whereasMG63 osteoblast-like cells proliferated well and covered the granule surfaces. The spheres with cerium chloride showed antibacterial properties against both gram-negative and gram-positive bacteria.

DOI： 10.3390/polym11101676

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Pseudogene YdfW in Escherichia coli decreases hydrogen production through nitrate respiration pathways 査読有り

Mokhtar M., Mohd Yusoff M., Mohamad Ali M., Mustapha N., Wood T., Maeda T.

International Journal of Hydrogen Energy 44 ( 31 ) 16212 - 16223 2019年06月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019 Hydrogen Energy Publications LLC Escherichia coli has approximately 4300 open reading frames and about 178 of them are annotated as pseudogenes. The existence of the pseudogenes in E. coli had raised the question of whether they contribute to any cell function. Recently, several pseudogenes have been studied; however, these genes are still considered rare and tend to be ignored as so-called junk. Our recent study has shown several pseudogenes in E. coli are essential in hydrogen metabolism. ydfW is one of the pseudogenes associated with hydrogen metabolism. Here, we found carbon dioxide and nitrate in the fermentation medium of mutant ydfW suggesting that this strain may induce nitrate pathways. The Fdh-N complex is comprised of FdnG, FdnH, and FdnI subunits which correspond to the nitrate-nitrite pathway. This finding is supported by transcription analysis that shows formate dehydrogenase (fdnG) and nitrate reductase (narG) are significantly induced (25- and 18-fold, respectively). FdnG and NarG play a significant role in the reduction of nitrate into nitrite; hence, their genes are induced by the build-up of nitrate. Based on in silico docking analysis, we predict that YdfW is covalently bound to the Fdh-N complex in the cytoplasm. Hence, deletion of ydfW is expected has influenced the nitrate-nitrite pathway. Subsequently, the situation will affect the hydrogen production in E. coli.

DOI： 10.1016/j.ijhydene.2019.04.228

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Quorum sensing between Gram-negative bacteria responsible for methane production in a complex waste sewage sludge consortium 査読有り

Nguyen P., Mustapha N., Kadokami K., Garcia-Contreras R., Wood T., Maeda T.

Applied Microbiology and Biotechnology 103 ( 3 ) 1485 - 1495 2019年02月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2018, Springer-Verlag GmbH Germany, part of Springer Nature. Quorum sensing (QS) plays a key role in activating bacterial functions through small molecules called autoinducers. In this study, the QS of Gram-negative bacteria in waste sewage sludge (WSS) was downregulated by adding the quorum quenching enzyme, AiiM lactonase, which cleaved the acyl-homoserine lactone (AHL) autoinducer signals from Gram-negative bacteria, and subsequently methane production was inhibited by over 400%. The pH was lowered after 2 days in the anaerobic fermentation whereas protease activity at the hydrolysis step was almost the same with or without AiiM. The production of acetic acid significantly increased during the fermentation in the presence of AiiM. The bacterial community at day 2 indicated that the population of Gram-positive bacteria increased in the presence of AiiM, and the percentage of Gram-negative bacteria decreased in the WSS containing AiiM. The change in the bacterial community in the presence of AiiM may be due to the different antimicrobial agents produced in the WSS because some of the Gram-positive bacteria were killed by adding the solid-phase extraction (SPE) fraction from the WSS without AiiM. In contrast, the SPE fraction with AiiM had reduced bactericidal activity against Gram-negative bacteria. Thus, bacterial signaling between Gram-negative bacteria is critical for methane production by the microbial consortia.

DOI： 10.1007/s00253-018-9553-9

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Dynamics of microbial populations responsible for biodegradation during the full-scale treatment of palm oil mill effluent 査読有り

Mohd-Nor D., Ramli N., Sharuddin S., Hassan M., Mustapha N., Ariffin H., Sakai K., Tashiro Y., Shirai Y., Maeda T.

Microbes and Environments 34 ( 2 ) 121 - 128 2019年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019, Japanese Society of Microbial Ecology. All rights reserved. Despite efforts to address the composition of the microbial community during the anaerobic treatment of palm oil mill effluent (POME), its composition in relation to biodegradation in the full-scale treatment system has not yet been extensively examined. Therefore, a thorough analysis of bacterial and archaeal communities was performed in the present study using MiSeq sequencing at the different stages of the POME treatment, which comprised anaerobic as well as facultative anaerobic and aerobic processes, including the mixed raw effluent (MRE), mixing pond, holding tank, and final discharge phases. Based on the results obtained, the following biodegradation processes were suggested to occur at the different treatment stages: (1) Lactobacillaceae (35.9%) dominated the first stage, which contributed to high lactic acid production; (2) the higher population of Clostridiaceae in the mixing pond (47.7%) and Prevotellaceae in the holding tank (49.7%) promoted acetic acid production; (3) the aceticlastic methanogen Methanosaetaceae (0.6–0.8%) played a role in acetic acid degradation in the open digester and closed reactor for methane generation; (4) Syntrophomonas (21.5–29.2%) appeared to be involved in the degradation of fatty acids and acetic acid by syntrophic cooperation with the hydrogenotrophic methanogen, Methanobacteriaceae (0.6–1.3%); and (5) the phenols and alcohols detected in the early phases, but not in the final discharge phase, indicated the successful degradation of lignocellulosic materials. The present results contribute to a better understanding of the biodegradation mechanisms involved in the different stages of the full-scale treatment of POME.

DOI： 10.1264/jsme2.ME18104

Scopus

CiNii Article

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Alcaligenaceae and Chromatiaceae as reliable bioindicators present in palm oil mill effluent final discharge treated by different biotreatment processes 査読有り

Mohd-Nor D., Ramli N., Sharuddin S., Hassan M., Mustapha N., Amran A., Sakai K., Shirai Y., Maeda T.

Ecological Indicators 95 468 - 473 2018年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2018 Elsevier Ltd This study was undertaken to confirm the reliability of the proposed potential bioindicators, Alcaligenaceae and Chromatiaceae to specifically indicate contamination in river water by palm oil mill effluent (POME) final discharge. The use of bioindicators could assist in determining the specific cause of contamination in water bodies. Alcaligenaceae and Chromatiaceae were shown by a previous study to be present in river water contaminated with the final discharge from the treatment of POME. In the present study, the compositions of the bacterial communities in the POME final discharge obtained from four different palm oil mills which used different biotreatments of POME were elucidated using high-throughput MiSeq. The four POME final discharges studied showed different species richness and evenness among them. However, the bacterial community compositions in the different final discharges exhibited almost similar patterns in that the phylum Proteobacteria was dominant in all the samples. The proposed bioindicators, the Alcaligenaceae and Chromatiaceae families, were found to be present in all the four final discharges despite the different characteristics of the mills and the different biotreatment processes used by them. These bioindicators were also strongly and positively correlated with the biochemical oxygen demand (BOD5) concentration. This makes them reliable bacterial indicators to detect the presence of POME final discharge in river water.

DOI： 10.1016/j.ecolind.2018.08.007

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Pseudogene product YqiG is important for pflB expression and biohydrogen production in Escherichia coli BW25113 査読有り

Zakaria M.

3 Biotech 8 ( 10 ) 2018年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2018, Springer-Verlag GmbH Germany, part of Springer Nature. Pseudogenes in the Escherichia coli genome are assumed to be non-functional. In this study, Keio collection BW25113∆yqiG and YqiG-producing strain (BW25113/pCA24N-YqiG) were used to evaluate the importance of pseudogene yqiG in hydrogen metabolism. Our results show pseudogene protein YqiG was identified as an essential protein in the production of biohydrogen from glucose. The mutant yqiG decreased biohydrogen production from 37 µmol mg−1protein to 6 µmol mg−1protein compared to the wild-type strain, and glucose consumption was reduced by 80%. Through transcriptional analysis, we found that the yqiG mutation represses pflB transcription tenfold; pflB encodes pyruvate-formate lyase, one of the key enzymes in the anaerobic metabolism of E. coli. Moreover, production of YqiG stimulated glycolysis and increased biohydrogen productivity 1.5-fold compared to that of the wild-type strain. Thus, YqiG is important for the central glycolysis reaction and is able to influence hydrogen metabolism activity in E. coli.

DOI： 10.1007/s13205-018-1461-2

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Electron carriers increase electricity production in methane microbial fuel cells that reverse methanogenesis 査読有り

Yamasaki R.

Biotechnology for Biofuels 11 ( 1 ) 2018年07月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2018 The Author(s). Background: We previously reversed methanogenesis in microbial fuel cells (MFCs) to produce electricity for the first time from methane by combining an engineered archaeal strain that produces methyl-coenzyme M reductase from unculturable anaerobic methanotrophs (to capture methane and secrete acetate) with Geobacter sulfurreducens (to produce electrons from the generated acetate) and methane-acclimated sludge (to provide electron shuttles). Results: Here, the power density in MFCs was increased 77-fold to 5216 mW/m2and the current density in MFCs was increased 73-fold to 7.3 A/m2by reducing the surface area of the cathode (to make reasonable comparisons to other MFCs), by changing the order the strains of the consortium were added to the anode compartment, and by adding additional electron carriers (e.g., humic acids and cytochrome C). Conclusions: This power density and current density are comparable to the best for any MFC, including those with Shewanella and Geobacter spp. that utilize non-gaseous substrates. In addition, we demonstrate the methane MFC may be used to power a fan by storing the energy in a capacitor. Hence, MFCs that convert methane to electricity are limited by electron carriers.

DOI： 10.1186/s13068-018-1208-7

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Enhanced phagocytosis of Aggregatibacter actinomycetemcomitans cells by macrophages activated by a probiotic Lactobacillus strain 査読有り

Jaffar N., Okinaga T., Nishihara T., Maeda T.

Journal of Dairy Science 101 ( 7 ) 5789 - 5798 2018年07月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2018 American Dairy Science Association The activation of phagocytosis is one important approach to clearing pathogenic cells in a host. This study evaluated the ability of probiotic lactobacilli to induce phagocytic activity as well as the clearance of a periodontal pathogen, Aggregatibacter actinomycetemcomitans. First, the activation of phagocytosis was found by using lyophilized dead cells. Probiotic Lactobacillus strains significantly enhanced the phagocytic activity of macrophage cells, indicating that the probiotic lactobacilli have a remarkable ability to stimulate the macrophages. Essentially, 3 Lactobacillus strains tested did not have any critical toxic effect on the murine macrophage, and Lactobacillus johnsonii NBRC 13952 showed the least cytotoxic effect on the RAW264.7 macrophages. The expression of classically activated macrophage markers, IL-1β, and cluster of differentiation 80 increased by L. johnsonii NBRC 13952; however, there was no significant difference for IL-18. The highest phagocytic activity by macrophages was found in a condition in which the macrophage activated by L. johnsonii NBRC 13952 functions to kill the cells of A. actinomycetemcomitans. Correlating with the result, a high amount of hypodiploid DNA (SubG1) was detected from the macrophage cells stimulated by L. johnsonii NBRC 13952. Taken together, the results suggest that macrophages activated by the Lactobacillus strain can facilitate the phagocytosis of A. actinomycetemcomitans cells by linking with enhanced apoptotic activities. In conclusion, L. johnsonii NBRC 13952 has a certain role in activating the RAW264.7 macrophages, thereby counteracting the infection of A. actinomycetemcomitans.

DOI： 10.3168/jds.2017-14355

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Pyocyanin restricts social cheating in Pseudomonas aeruginosa 査読有り

Castañeda-Tamez P., Ramírez-Peris J., Pérez-Velázquez J., Kuttler C., Jalalimanesh A., Saucedo-Mora M., Jiménez-Cortés J., Maeda T., González Y., Tomás M., Wood T., García-Contreras R.

Frontiers in Microbiology 9 ( JUN ) 2018年06月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2018 Castañeda-Tamez, Ramírez-Peris, Pérez-Velázquez, Kuttler, Jalalimanesh, Saucedo-Mora, Jiménez-Cortés, Maeda, González, Tomás, Wood and García-Contreras. Quorum sensing (QS) in Pseudomonas aeruginosa coordinates the expression of virulence factors, such as exoproteases and siderophores, that are public goods utilized by the whole population of bacteria, regardless of whether they invested or not in their production. These public goods can be used by QS defective mutants for growth, and since these mutants do not contribute to public goods production, they are considered social cheaters. Pyocyanin is a phenazine that is a toxic, QS-controlled metabolite produced by P. aeruginosa. It is a redox-active compound and promotes the generation of reactive oxygen species; it also possesses antibacterial properties and increases fitness in competition with other bacterial species. Since QS-deficient individuals are less able to tolerate oxidative stress, we hypothesized that the pyocyanin produced by the wild-type population could promote selection of functional QS systems in this bacterium. Here, we demonstrate, using competition experiments and mathematical models, that, indeed, pyocyanin increases the fitness of the cooperative QS-proficient individuals and restricts the appearance of social cheaters. In addition, we also show that pyocyanin is able to select QS in other bacteria such as Acinetobacter baumannii.

DOI： 10.3389/fmicb.2018.01348

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Seeking key microorganisms for enhancing methane production in anaerobic digestion of waste sewage sludge 査読有り

Mustapha N., Hu A., Yu C., Sharuddin S., Ramli N., Shirai Y., Maeda T.

Applied Microbiology and Biotechnology 102 ( 12 ) 5323 - 5334 2018年06月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2018, Springer-Verlag GmbH Germany, part of Springer Nature. Efficient approaches for the utilization of waste sewage sludge have been widely studied. One of them is to use it for the bioenergy production, specifically methane gas which is well-known to be driven by complex bacterial interactions during the anaerobic digestion process. Therefore, it is important to understand not only microorganisms for producing methane but also those for controlling or regulating the process. In this study, azithromycin analogs belonging to macrolide, ketolide, and lincosamide groups were applied to investigate the mechanisms and dynamics of bacterial community in waste sewage sludge for methane production. The stages of anaerobic digestion process were evaluated by measuring the production of intermediate substrates, such as protease activity, organic acids, the quantification of bacteria and archaea, and its community dynamics. All azithromycin analogs used in this study achieved a high methane production compared to the control sample without any antibiotic due to the efficient hydrolysis process and the presence of important fermentative bacteria and archaea responsible in the methanogenesis stage. The key microorganisms contributing to the methane production may be Clostridia, Cladilinea, Planctomycetes, and Alphaproteobacteria as an accelerator whereas Nitrosomonadaceae and Nitrospiraceae may be suppressors for methane production. In conclusion, the utilization of antibiotic analogs of macrolide, ketolide, and lincosamide groups has a promising ability in finding the essential microorganisms and improving the methane production using waste sewage sludge.

DOI： 10.1007/s00253-018-9003-8

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Current state and perspectives in hydrogen production by Escherichia coli: roles of hydrogenases in glucose or glycerol metabolism 招待有り査読有り

Maeda T., Tran K., Yamasaki R., Wood T.

Applied Microbiology and Biotechnology 102 ( 5 ) 2041 - 2050 2018年03月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2018, Springer-Verlag GmbH Germany, part of Springer Nature. Escherichia coli has been a robust host strain for much biological research, in particular, research in metabolic engineering, protein engineering, and heterologous gene expression. In this mini review, to understand bacterial hydrogen production by E. coli, the effect of glucose and glycerol metabolism on hydrogen production is compared, and the current approaches to enhance hydrogen production from glycerol as a substrate are reviewed. In addition, the argument from past to present on the functions of E. coli hydrogenases, hydrogenase 1, hydrogenase 2, hydrogenase 3, and hydrogenase 4 is summarized. Furthermore, based on the literature that the E. coli formate-hydrogen lyase is essential for bacterial hydrogen production via recombinant hydrogenases, research achievements from the past regarding heterologous production of hydrogenase are rethought.

DOI： 10.1007/s00253-018-8752-8

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Shift of low to high nucleic acid bacteria as a potential bioindicator for the screening of anthropogenic effects in a receiving river due to palm oil mill effluent final discharge 査読有り

Sharuddin S., Ramli N., Mohd-Nor D., Hassan M., Maeda T., Shirai Y., Sakai K., Tashiro Y.

Ecological Indicators 85 79 - 84 2018年02月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2017 Elsevier Ltd The microbiological effects of palm oil mill effluent (POME) final discharge upon a receiving river were assessed in this study by using the nucleic acid double staining assay based on flow cytometry. The functional status of the bacterial community at the single-cell level was determined with regards to their abundance, viability and nucleic acid content to monitor the effects of POME final discharge on the affected river. The effluent resulted in the increment of the total cell concentration (TCC) and viable cells which were correlated with the increment of biological oxygen demand (BOD5) and total organic carbon (TOC) concentrations in the receiving river. The shift of low nucleic acid (LNA) to high nucleic acid (HNA) bacterial cells in the affected river suggested the transformation of dormant to active cells due to the POME final discharge. This is the first study to report on the shift of LNA/HNA ratios which may serves as a potential bioindicator in the screening of the anthropogenic effects due to POME final discharge in river water with originally high LNA proportions. Monitoring the effluent discharge at low trophic level using flow cytometry is a rapid and sensitive approach when compared to the current physicochemical assessment method. This approach allows for the screening of river water contamination caused by POME final discharge prior to a full assessment using the recently proposed specific bacterial indicators.

DOI： 10.1016/j.ecolind.2017.10.020

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Improvement of (R,R)-2,3-butanediol production from corn stover hydrolysate by cell recycling continuous fermentation 査読有り

Ma K., He M., You H., Pan L., Wang Z., Wang Y., Hu G., Cui Y., Maeda T.

Chemical Engineering Journal 332 361 - 369 2018年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2017 Elsevier B.V. To achieve industrial (R,R)-2,3-butanediol ((R,R)-2,3-BDL) production from various lignocellulosic biomass, it is essential to develop an efficient fermentation process to overcome the challenge of carbon catabolite repression (CCR). The present study comprehensively investigated the effects of different glucose/xylose mixtures and fermentation strategies on (R,R)-2,3-BDL production using a nonpathogenic strain of Paenibacillus polymyxa. In both batch and fed-batch mode, we observed slow sugar utilization and a lower productivity. By employing cell-recycling continuous fermentation system for (R,R)-2,3-BDL production from mixed sugar, the volumetric productivity was significantly increased, by an average of 2-fold higher compared to alternative fermentation modes. Moreover, the (R,R)-2,3-BDL titer, volumetric productivity and yield achieved 18.80 g/l, 1.13 g/l/h and 0.313 g/g when corn stover hydrolysates (CSH)was used as substrate. The results suggested that the reported fermentation system could efficiently eliminate CCR to improve (R,R)-2,3-BDL productivity. Thus, it had great potential for the industrial-scale (R,R)-2,3-BDL production from lignocellulosic hydrolysates.

DOI： 10.1016/j.cej.2017.09.097

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Triple knockout of frdC gltA and pta genes enhanced PHA production in escherichia coli 査読有り

Biran N., Yusoff M., Maeda T., Zakaria M., Yee L., Hassan M.

Asia-Pacific Journal of Molecular Biology and Biotechnology 26 ( 1 ) 11 - 18 2018年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2018, University of Malaya. All rights reserved. Polyhydroxyalkanoate (PHA) is a linear polyester produced through the fermentation of sugar or lipid. Biosynthesis of PHA comprises three enzymes known as acetyl-CoA acetyltransferase (phaA), acetoacetyl-CoA reductase (phaB) and PHA synthase (phaC). Comamonas sp. is one of the strains commonly used for PHA production. In order to develop higher PHA production from bacterial respond strategy, PHA biosynthesis operon of Comamonas sp. EB172 was introduced into Escherichia coli BW25113 through a pGEM-T vector. E. coli was chosen due to the complete genome information available and the absence of depolymerisation gene, phaZ. In this study, the deletion of several single genes, which are frdC, gltA, and pta, was found to be associated with PHA metabolism activity in E. coli BW25113. P1 transduction was performed to construct multiple genes knockout. The engineered strain, E. coli BW25113 frdCgltApta::kan/pGEM’-phaCAB Co , yielded the highest PHA production at 64 wt.% with 1.4 fold higher than that of control strain of E. coli BW25113/pGEM’-phaCAB Co . This strain is potential for industrial application for higher PHA production from E. coli.

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Selection of Functional Quorum Sensing Systems by Lysogenic Bacteriophages in Pseudomonas aeruginosa 査読有り

Miguel A. Saucedo-Mora, Paulina Castañeda-Tamez, Adrián Cazares, Judith Pérez-Velázquez, Burkhard A. Hense, Daniel Cazares, Wendy Figueroa, Marco Carballo, Gabriel Guarneros, Berenice Pérez-Eretza, Nelby Cruz, Yoshito Nishiyama, Toshinari Maeda, Javier A. Belmont-Díaz, Thomas K. Wood, Rodolfo García-Contreras

Frontiers in Microbiology 8 Article 1669 2017年08月

Inhibition of methane production by the palm oil industrial waste phospholine gum in a mimic enteric fermentation 査読有り

Nurul Asyifah Mustapha, Siti Suhailah Sharuddin, Mohd Huzairi Mohd Zainudin, Norhayati Ramli, Yoshihito Shirai, Toshinari Maeda

Journal of Cleaner Production 165 621 - 629 2017年07月

Bacterial community shift revealed Chromatiaceae and Alcaligenaceae as potential bioindicators in the receiving river due to palm oil mill effluent final discharge 査読有り

Siti Suhailah Sharuddin, Norhayati Ramli, Mohd Ali Hassan, Nurul Asyifah Mustapha, Afufira Amran, Diana Mohd-Nor, Kenji Sakai, Yukihiro Tashiro, Yoshihito Shirai, Toshinari Maeda

Ecological Indicators 82 526 - 529 2017年07月

Enhanced fuel ethanol production from rice straw hydrolysate by an inhibitor-tolerant mutant strain of Scheffersomyces stipitis 査読有り

Kedong Ma, Mingxiong He, Huiyan You, Liwei Pan, Guoquan Hu, Yubo Cuic, Toshinari Maeda

RSC Advances 7 31180 2017年06月

Oceans as bioenergy pools for methane production using activated methanogens in waste sewage sludge 査読有り

Nazlina Haiza Mohd Yasin, Azusa Ikegami, Thomas K. Wood, Chang-Ping Yu, Tetusya Haruyama, Mohd Sobri Takriff, Toshinari Maeda

Applied Energy 202 399 - 407 2017年05月

Elucidating substrate utilization in biohydrogen production from palm oil mill effluent by Escherichia coli 査読有り

Azam Fikri Taifor, Mohd Rafein Zakaria, Mohd Zulkhairi Mohd Yusoff, Toshinari Maeda, Mohd Ali Hassan

International Journal of Hydrogen Energy 42 ( 9 ) 5812 - 5819 2017年03月

Exploiting quorum sensing inhibition for the control of Pseudomonas aeruginosa and Acinetobacter baumannii biofilms 査読有り

Israel Castillo-Juarez, Luis Esaú López-Jácome, Gloria Soberón-Chávez, María Tomás, Jintae Lee, Paulina Castañeda-Tamez, Iván Ángelo Hernández-Bárragan, Martha Yumiko Cruz-Muñiz, Toshinari Maeda, Thomas K. Wood,Rodolfo García-Contreras

Current Topics in Medicinal Chemistry 2017年01月

下水汚泥のメタン発酵向上化のための細菌間相互作用の解明

前田憲成

環境バイオテクノロジー学会誌 ( 環境バイオテクノロジー学会 ) 16 ( 1 ) 17 - 21 2016年12月

Structural chromosome aberrations cause swelling of the nucleus 査読有り

Kenji Takeshita, Hiroaki I. Ogawa, Toshinari Maeda

Genes and Environment 38 22 2016年10月

Impact of different antibiotics on methane production using waste-activated sludge: mechanisms and microbial community dynamics 査読有り

Nurul Asyifah Mustapha, Kenji Sakai, Yoshihito Shirai, Toshinari Maeda

Applied Microbiology and Biotechnology 100 ( 21 ) 9355 - 9364 2016年08月

Biofilm formation of periodontal pathogens on hydroxyapatite surfaces: implications for periodontium damage 査読有り

Norzawani Jaffar, Toshiki Miyazaki, Toshinari Maeda

Journal of Biomedical Materials Research Part A 104 ( 11 ) 2873 - 2880 2016年07月

Mature biofilm degradation by potential probiotics: Aggregatibacter actinomycetemcomitans versus Lactobacillus spp. 査読有り

Norzawani Jaffar, Yuya Ishikawa, Kouhei Mizuno, Toshinori Okinaga, Toshinari Maeda

PLoS One 11 e0159466 2016年07月

The prevalence of foodborne pathogenic bacteria on cutting boards and their ecological correlation with background biota 査読有り

Noor-Azira Abdul-Mutalib, Syafinaz Amin Nordin, Malina Osman, Ahmad Muhaimin Roslan, Matsumi Ishida, Kenji Sakai, Yukihiro Tashiro, Kosuke Tashiro, Toshinari Maeda, Yoshihito Shirai

AIMS Microbiology 2 ( 2 ) 138 - 151 2016年05月

Rapid screening method for isolation of glycerol-consuming bacteria for ethanol production 査読有り

Suhaimi S., Adnan N., Yee P., Abd-Aziz S., Maeda T.

Sains Malaysiana 45 ( 5 ) 811 - 815 2016年05月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2016, Penerbit Universiti Kebangsaan Malaysia. All rights reserved.Large numbers of glycerol-consuming bacteria are present in nature; hence bioconversion of glycerol into biofuel which is bioethanol is one of the interests. The effective screening procedure is needed to screen and isolate broad ranges of bacteria from environment. The screening method was modified based on enzymatic oxidation of ethanol, which is correlated to reduction of 2,6-dichlorophenol-indophenol dye that resulted in the formation of yellow zone. Approximately 300 colonies were able to grow on minimal media using glycerol as sole carbon. Only about 70 isolates showed positive result when using the modified ethanol production assay after pre-screening stage. The formation of decolourized zone was apparent using modified assay containing 5 mL/L of 0.05M 2,6-dichlorophenol-indophenol, 10 mL of reaction mixture and 500 μl/L of enzyme, respectively. The ethanol production capability of the isolates was further proven by anaerobic fermentation as a quantitative method. This modified method is applicable in screening for ethanol producer from glycerol as carbon source allows rapid and more bacteria can be screened.

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Can resistance against quorum-sensing interference be selected? 査読有り

Rodolfo García-Contreras, Toshinari Maeda, Thomas K. Wood

ISME Journal 10 ( 1 ) 4 - 10 2016年01月

The prevalence of foodborne pathogenic bacteria on cutting boards and their ecological correlation with background biota 査読有り

Abdul-Mutalib N.A., Nordin S.A., Osman M., Roslan A.M., Ishida N., Sakai K., Tashiro Y., Tashiro K., Maeda T., Shirai Y.

AIMS Microbiology 2 ( 2 ) 138 - 151 2016年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

This study implemented the pyrosequencing technique and real-time quantitative PCR to determine the prevalence of foodborne pathogenic bacteria (FPB) and as well as the ecological correlations of background biota and FPB present on restaurant cutting boards (CBs) collected in Seri Kembangan, Malaysia. The prevalence of FPB in high background biota (HBB) was lower (0.24%) compared to that of low background biota (LBB) (0.54%). In addition, a multiple linear regression analysis indicated that only HBB had a significant ecological correlation with FPB. Furthermore, statistical analysis revealed that the combinations of Clostridiales, Flavobacteriales, and Lactobacillales orders in HBB had significant negative associations with FPB, suggesting that these bacteria may interact to ensure survivability and impair the growth of pathogenic bacteria.

DOI： 10.3934/MICROBIOL.2016.2.138

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High variability in quorum quenching and growth inhibition by furanone C-30 in Pseudomonas aeruginosa clinical isoaltes from cystic fibrosis patients 査読有り

Rodolfo García-Contreras, Berenice Peréz-Eretza, Ricardo Jasso-Chávez, Elizabeth Lira-Silva, Jesús Alberto Roldán-Sánchez, AbigailGonzález-Valdez, Gloria Soberón-Chávez, Rafael Coria-Jiménez, Mariano Martínez-Vázquez, Luis David Alcaraz, Toshinari Maeda,Thomas K. Wood

Pathogenes and Disease 73 ( 6 ) ftv040 2015年08月

Role of quorum sensing in bacterial infections 査読有り

Israel Castillo-Juárez, Toshinari Maeda, Edna Ayerim Mandujano-Tinoco, María Tomás, Berenice Pérez-Eretza, Silvia Julieta García-Contreras, Thomas K Wood, Rodolfo García-Contreras

World Journal of Clinical Cases 3 ( 7 ) 575 - 598 2015年07月

Pyrosequecning analysis of microbial community and food-borne bacteria on restanrant cutting boards collected in Seri Kembangan, Malaysia, and their correlation with grades of food premises 査読有り

Noor-Azira Abdul-Mutalib, Syafinaz Amin Nordin, Malina Osman, Natsumi Ishida, Kosuke Tashiro, Kenji Sakai, Yukihiro Tashiro, Toshinari Maeda, Yoshihito Shirai

International Journal of Food Microbiology 200 57 - 65 2015年05月

Beneficial knockouts in Escherichia coli for producing hydrogen from glycerol 査読有り

Kien Trung Tran, Toshinari Maeda, Viviana Sanchez-Torres, Thomas K. Wood

Applied Microbiology and Biotechnology 99 ( 6 ) 2573 - 2581 2015年03月

CO2 sequestration by methanogens in activated sludge for methane production 査読有り

Nazlina Haiza Mohd Yasin, Toshinari Maeda, Anyi Hu, Chang-Ping Yu, Thomas K. Wood

Applied Energy 142 426 - 434 2015年03月

Quorum sensing enhancement of the stress response promotes resistance to quorum quenching and prevents social cheating 査読有り

Rodolfo García-Contreras, Leslie Nuñez-López, Ricardo Jasso-Chávez, Brian W Kwan, Javier A Belmont, Adrián Rangel-Vega, Toshinari Maeda, Thomas K Wood

The ISME Journal 9 ( 1 ) 115 - 125 2015年01月

Enhancement of sludge reduction and methane production by removing extracellular polymeric substances from waste activated sludge 査読有り

Minh Tuan Nguyen, Nazlina Haiza Mohd Yasin, Toshiki Miyazaki, Toshinari Maeda

Chemosphere 117 552 - 558 2014年12月

Enhanced reduction of waste activated sludge at a low temperature by locally isolated strains Pseudomonas sp. VNT and Aeromonas sp. VNT 査読有り

Nazlina Haiza Mohd Yasin, Viviana Sanchez-Torres, Toshinari Maeda

Bioresource Technology 174C 134 - 141 2014年10月

Effect of azithromycin on enhancement of methane production from waste activated sludge 査読有り

Minh Tuan Nguyen, Toshinari Maeda, Mohd Zulkhairi Mohd Yusoff, Hiroaki I. Ogawa

Journal of Industrial Microbiology and Biotechnology 41 ( 7 ) 1051 - 1059 2014年07月

Metabolic engineering of Escherichia coli to enhance hydrogen production from glycerol 査読有り

Kien Trung Tran, Toshinari Maeda, Thomas K. Wood

Applied Microbiology and Biotechnology 98 ( 10 ) 4757 - 4770 2014年05月

A rapid colorimetric screening method for vanillic acid and vanillin-producing bacterial strains 査読有り

Nur Ain Zamzuri, Suraini Abd-Aziz, Raha Abdul Rahim, Lai Yee Phang, Noorjahan Banu Alitheen, Toshinari Maeda

Journal of Applied Microbiology 116 ( 4 ) 903 - 910 2014年04月

Biodegradation of a quorum sensing inhibitor, C-30 by Pseudomonas aeruginosa: Survival strategy and environmental bio-adaptation 査読有り

Toshinari Maeda

AFOB Regional Symposium 2014 2014年02月

Gallium induces the production of virulence factors in Pseudomonas aeruginosa 査読有り

Rodolfo García-Contreras, Berenice Pérez, Elizabeth Lira-Silva, Ricardo Jasso-Chávez, Rafael Coria-Jiménez, Adrián Rangel-Vega, Toshinari Maeda, Thomas K. Wood

Pathogens and Disease 70 ( 1 ) 95 - 98 2014年02月

Open fermentative production of l-lactic acid with high optical purity by thermophilic Bacillus coagulans using excess sludge as nutrient 査読有り

Kedong Ma, Toshinari Maeda, Huiyan You, Yoshihito Shirai

Bioresource Technology 151 28 - 35 2014年01月

Isolation and characterization of Gallium resistant Pseudomonas aeruginosa mutants 査読有り

Rodolfo García-Contreras, Elizabeth Lira-Silva, Ricardo Jasso-Chávez, Ismael L Hernández-González, Toshinari Maeda, Takahiro Hashimoto, Fred C. Boogerd, Lili Sheng, Thomas K. Wood, Rafael Moreno-Sánchez

International Journal of Medical Microbiology 303 ( 8 ) 574 - 582 2013年12月

細菌溶菌性Bdellovibrio属細菌のpH環境に依存した大腸菌捕食機構の解明

吉村純一, 前田憲成

環境バイオテクノロジー学会誌 ( 環境バイオテクノロジー学会 ) 13 ( 2 ) 145 - 149 2013年12月

Enhancement of sludge reduction and methane production by the removal of extracellular polymeric substances from wasted activated sludge 査読有り

Minh Tuan Nguyen, Mohd Zulkhairi Mohd Yusoff, Toshinari Maeda

Bioenergy Korea Conference 2013 International Symposium 365 2013年11月

Biological conversion of carbon dioxide to methane using sewage sludge 査読有り

Nazlina Haiza Mohd Yasin, Toshinari Maeda

Bioenergy Korea Conference 2013 International Symposium 368 2013年11月

Metabolic engineering to enhance and optimize hydrogen production from glycerol by Escherichia coli 査読有り

Kien Trung Tran, Toshinari Maeda

Bioenergy Korea Conference 2013 International Symposium 370 2013年11月

Resistance to quorum quenching compoudns 査読有り

Rodolfo García-Contreras, Toshinari Maeda, Thomas K. Wood

Applied and Environmental Microbiology 79 ( 22 ) 6840 - 6846 2013年11月

Four products from Escherichia coli pseudogenes increase hydrogen production 査読有り

Mohd Zulkhairi Mohd Yusoff, Yuya Hashiguchi, Toshinari Maeda, Thomas K. Wood

Biochemical and Biophysical Research Communications 439 ( 4 ) 576 - 579 2013年10月

Influence of pretreated activated sludge for electricity generation in microbial fuel cell application 査読有り

Mohd Zulkhairi Mohd Yusoff, Anyi Hu, Cuijie Feng, Toshinari Maeda, Yoshihito Shirai, Mohd Ali Hassan, Chang-Ping Yu

Bioresource Technology 145 90 - 96 2013年10月

Biohydrogen production from oil palm frond juice and sewage sludge by a metabolically engineered Escherichia coli strain 査読有り

Nazlina Haiza Mohd Yasin, Masaharu Fukuzaki, Toshinari Maeda, Toshiki Miyazaki, Che Mohd Hakiman Che Maail, Hidayah Ariffin, Thomas K. Wood

International Journal of Hydrogen Energy 38 ( 25 ) 10277 - 10283 2013年08月

Escherichia coli Pseudogenes are Related to Bacterial Hydrogen Production 査読有り

Yuya Hashiguchi, Mohd Zulkhairi Mohd Yusoff, Toshinari Maeda

2013-The 9th Asia Pacific Conference on Sustainable Energy & Environmental Technologies 2013年07月

New functional protein, YhjY, in Escherichia coli known to be essential protein in biohydrogen metabolism 査読有り

Mohd Zulkhairi Mohd Yusoff, Yuya Hashiguchi, Toshinari Maeda

2013-The 9th Asia Pacific Conference on Sustainable Energy & Environmental Technologies 2013年07月

Improvement of cyclodextrin glycosyltransferase gene expression in Escherichia coli by insertion of regulatory sequences involved in the promotion of RNA transcription 査読有り

Norhayati Ramli, Suraini Abd-Aziz, Noorjahan Banu Alitheen, Mohd Ali Hassan, Toshinari Maeda

Molecular Biotechnology 54 ( 3 ) 961 - 968 2013年06月

Resistance to the quorum quenching compounds brominated furanone C-30 and 5-fluorouracil in Pseudomonas aeruginosa clinical isolates 査読有り

Rodolfo García-Contreras,Mariano Martínez-Vázquez, Alejandra Guadalupe Villegas-Pañeda, Takahiro Hashimoto, Toshinari Maeda, Héctor Quezada, Thomas K. Wood

Pathogens and Disease 68 ( 1 ) 8 - 11 2013年06月

Real-time PCR for rapidly detecting aniline-degrading bacteria in activated sludge 査読有り

Takakazu Kayashima, Hisako Suzuki, Toshinari Maeda, Hiroaki I. Ogawa

Chemosphere 91 ( 9 ) 1338 - 1343 2013年05月

Influence of Escherichia coli hydrogenases on hydrogen fermentation from glycerol 査読有り

Viviana Sanchez-Torres, Mohd Zulkhairi Mohd Yusoff, Chieri Nakano, Toshinari Maeda, Hiroaki I. Ogawa, Thomas K. Wood

International Journal of Hydrogen Energy 38 ( 10 ) 3905 - 3912 2013年04月

緑膿菌によるクォーラムセンシング阻害剤C-30の代謝変換と阻害効果の追及

橋本卓宏, 前田憲成, 門上希和夫, Rodolfo Garcia-Contreras, Thomas K. Wood, 尾川博昭

環境バイオテクノロジー学会誌 ( NPO法人環境バイオテクノロジー学会 ) 12 ( 2 ) 129 - 133 2012年12月

Effect of acylhomoserine lactones (AHL)to thermophilic aerobic digestion and methanefermentation of waste activated sludge 査読有り

Tsuneoka Y., Maeda T., Nakano K.

The 25th International Symposium on Chemical Engineering (25 thISCE2012) 2012年12月

Study on development of a new sewage treatment flow system for excess sludge reduction and resource recovery 査読有り

Nguyen M. T., Tsumori Y., Nishino T., Yamashita T., Nakano K., Maeda T.

The 25th International Symposium on Chemical Engineering (25 thISCE2012) 2012年12月

Uncharacterized Escherichia coli proteins YdjA and YhjY are related to biohydrogen production 査読有り

Mohd Yusoff M. Z., Maeda T., Sanchez-Torres V., Ogawa H. I., Shirai Y., Hassan M. A., Wood T. K.

International Journal of Hydrogen Energy 37 ( 23 ) 17778 - 17787 2012年12月

Microbial fuel cells using activated sewage sludge for electricity generation 査読有り

Mohd Yusoff M. Z., Feng C., Hu A., Maeda T., Shirai Y., Ogawa H. I., Hassan M. A., Yu C.-P.

15th International Biotechnology Symposium and Exhibition (IBS 2012) 2012年09月

Bioconversion of glycerol for bioethanol production using isolated Escherichia coli SS1 査読有り

Suhaimi S. N., Phang L.-Y., Maeda T., Abd-Aziz S., Wakisaka M., Shirai Y., Hassan M. A.

Brazilian Journal of Microbiology 43 ( 2 ) 506 - 516 2012年04月

Quorum quenching quandary: resistance to antivirulence compounds 査読有り

Toshinari Maeda, Rodolfo Garcia-Contreras, Mingming Pu, Lili Sheng, Luis Rene Garcia, Maria Tomas, Thomas K. Wood

The ISME Journal 6 ( 3 ) 493 - 501 2012年03月

Hydrogen production by recombinant Escherichia coli strains 招待有り査読有り

Toshinari Maeda, Viviana Sanchez-Torres, Thomas K. Wood

Microbial Biotechnology 5 ( 2 ) 214 - 225 2012年03月

Reduction of sewage excess sludge by using biological together with alkali treatment 査読有り

Hirofumi Nakashima, Kouichi Nakano, Toshinari Maeda, Hiroaki I. Ogawa

The 24th International Symposium on Chemical Engineering 2011年12月

Investigation of biological implication for metabolism of a quorum sensing inhibitor by Pseudomonas aeruginosa 査読有り

Takahiro Hashimoto, Toshinari Maeda, Kiwao Kadokami, Rodolfo Garcia-Contreras, Thomas K. Wood, Kouichi Nakano, Hiroaki I. Ogawa

The 24th International Symposium on Chemical Engineering 2011年12月

Study on development of a new sewage treatment flow system for reducing the amount of excess sludge 査読有り

Yusuke Tomita, Kouichi Nakano, Toshinari Maeda, Hiroaki I. Ogawa

The 24th International Symposium on Chemical Engineering 2011年12月

Purification and characterization of a serine protease secreted by Brevibacillus sp. KH3 for reducing waste activated sludge and biofilm formation 査読有り

Toshinari Maeda, Takayuki Yoshimura, Rodolfo Garcia-Contreras, Hiroaki I. Ogawa

Bioresource Technology 102 ( 22 ) 10650 - 10656 2011年11月

Functional analysis of an important gene related to biohydrogen production in Escherichia coli 査読有り

Mohd Zulkhairi Mohd Yusoff, Toshinari Maeda, Viviana Sanchez-Torres, Thomas K. Wood, Yoshihito Shirai, Hiroaki I. Ogawa, Mohd Ali Hassan

BioMicroWorld 2011, IV International Conference on Environmental, Industrial and Applied Microbiology 2011年09月

Quorum quenching quandary: resistance to antivirulence compounds 査読有り

Toshinari Maeda, Rodolfo Garcia-Contreras, Mingming Pu, Lili Sheng, Hiroaki I. Ogawa, Luis Rene Garcia, Maria Tomas, Wendy Rangel, Thomas K. Wood

BioMicroWorld 2011, IV International Conference on Environmental, Industrial and Applied Microbiology 2011年09月

Cell adhesion, aggregability, and biofilm formation of Streptococcus sanguinis for understanding the formation of bloated blood clot 査読有り

Toshinari Maeda, Ryosuke Saeki, Masaki Morishita, Hiroaki I. Ogawa, Toshinori Okinaga, Wataru Ariyoshi, Tatsuji Nishihara

IUMS 2011 Congress, XIII International Congress of Bacteriology and Applied Microbiology 2011年09月

高度水素生産菌株を活用した迅速な安全性評価技術の開発査読有り

前田憲成, 有吉弘貴, 高柳聖, 尾川博昭

用水と廃水 53 ( 6 ) 458 - 464 2011年06月

Role of pili in S. sanguinis to the cell adhesion 査読有り

R. Saeki,M. Morishita,T. Maeda,H. I. Ogawa,T. Okinaga,W. Ariyoshi,T. Nishihara

The 58th Annual Meeting of Japanese Association for Dental Research (JADR2010) 124 - 124 2010年11月

Global regulator H-NS and lipoprotein NlpI influence production of extracellular DNA in Escherichia coli 査読有り

Viviana Sanchez-Torres,Toshinari Maeda,Thomas K. Wood

Biochemical and Biophysical Research Communication 401 ( 2 ) 197 - 202 2010年10月

下水汚泥減容を微生物により行う汚水処理プロセスエネルギーのエコフィッティング

前田憲成,毛利謙太郎,高石万理,中野光一,尾川博昭

先端エコフィッティング技術研究開発センター紀要 ( 2 ) 63 - 86 2010年09月

Behaviour of DNA components during thermophilic aerobic digestion of waste activated sludge by Brevibacillus sp. KH3 査読有り

K. Mouri,T. Maeda,H. I. Ogawa

14th International Biotechnology Symposium and Exhibition P-E.71 2010年09月

Biological treatment of harmful TNT wastewater containing a high concentration of nitrogen compounds by waste activated sludge 査読有り

Ryosuke Saeki,Toshinari Maeda,Yoichiro Harada,Nobuo Nagayasu,Hiroaki I. Ogawa

14th International Biotechnology Symposium and Exhibition (IBS2010) P-E.41 2010年09月

Construction of simple and rapid toxicity assay with a metabolically-engineered hyper hydrogen-producing Escherichia coli strain 査読有り

Sei Takayanagi,Toshinari Maeda,Hiroaki I. Ogawa,Thomas K. Wood

Systems Biology of Microorganisms 81 - 81 2010年03月

How sludge-lysing bacteria behave in waste activated sludge: The roles of extracellular enzymes 査読有り

Mari Takaishi,Toshinari Maeda,Kentaro Mouri,Hiroaki I. Ogawa

Systems Biology of Microorganisms 80 - 80 2010年03月

大腸菌の代謝改変およびタンパク質改変による水素ガスの高度生産化

前田憲成,尾川博昭

環境バイオテクノロジー学会誌 ( 未設定 ) 9 ( 2 ) 69 - 74 2009年12月

Purification and characterization of a serine protease secreted from Brevibacillus sp. KH3 for reducing excess sludge and biofilm formation 査読有り

Toshinari Maeda,Takayuki Yoshimura,Hiroaki I. Ogawa

Journal of Bioscience and Bioengineering (APBioChEC'09-Biotechnology for Sustainable Development-) 108 ( S1 ) S80 - S81 2009年11月

Enhanced production of lactic acid with reducing excess sludge by lactate fermentation 査読有り

Toshinari Maeda,Takayuki Yoshimura,Tomohiko Shimazu,Yoshihito Shirai,Hiroaki I. Ogawa

Journal of Hazardous Materials 168 ( 2-3 ) 656 - 663 2009年09月

Protein engineering of the transcriptional activator FhlA To enhance hydrogen production in Escherichia coli 査読有り

Viviana Sanchez-Torres,Toshinari Maeda,Thomas K. Wood

Applied and Environmental Microbiology 75 ( 17 ) 5639 - 5646 2009年09月

下水汚泥を溶解する新規高温性細菌株による汚泥処理の省力化

高石万理,前田憲成,中野光一,尾川博昭

先端エコフィッティング技術研究開発センター紀要 ( 1 ) 46 - 46 2009年05月

Isolation, identification of sludge-lysing strain and its utilization in thermophilic aerobic digestion for waste activated sludge 査読有り

Xuesong Li,Hongzhi Ma,Qunhui Wang,Shoichiro Matsumoto,Toshinari Maeda,Hiroaki I. Ogawa

Bioresource Technology 100 ( 9 ) 2475 - 2481 2009年05月

下水汚泥溶解細菌Brevibacillus sp. KH3株の産生するタンパク質分解酵素に関する研究

吉村貴之,波戸利明,前田憲成,尾川博昭

歯工学連携キックオフシンポジウム－歯工学連携の目指す生活の質（QOL)の向上－ 69 - 71 2009年03月

Pseudomonas属細菌TM15株の2,4,6-トリニトロトルエン生分解遺伝子に関する研究

西河良諭,前田憲成,尾川博昭

歯工学連携キックオフシンポジウム－歯工学連携の目指す生活の質（QOL)の向上－ 72 - 76 2009年03月

Reconfiguring the quorum-sensing regulator SdiA of Escherichia coli to control biofilm formation via indole and N-acylhomoserine lactones 査読有り

Jintae Lee,Toshinari Maeda,Seok Hoon Hong,Thomas K. Wood

Applied and Environmental Microbiology 75 ( 6 ) 1703 - 1716 2009年03月

生物機能を利用した火薬センサの最前線

前田憲成

生物工学会誌 ( 未設定 ) 87 ( 1 ) 21 2009年01月

シュードモナス属細菌TM15株の2,4,6-トリニトロトルエン生分解遺伝子に関する研究

西河良諭,前田憲成,尾川博昭

環境バイオテクノロジー学会誌 ( 未設定 ) 8 ( 2 ) 95 - 97 2008年12月

TNT biodegradation and production of dihydroxylamino-nitrotoluene by aerobic TNT degrader Pseudomonas sp. strain TM15 in an anoxic environment 査読有り

Akira Kubota,Toshinari Maeda,Nobuaki Nagafuchi,Kiwao Kadokami,Hiroaki I. Ogawa

Biodegradation 19 ( 6 ) 795 - 805 2008年11月

Enhanced digestion of waste activated sludge (WAS) by thermophilic WAS-lysing bacteria 査読有り

Xuesong Li,Shoichiro Matsumoto,Qunhui Wang,Toshinari Maeda,Hiroaki I. Ogawa

Journal of Biotechnology/Biotechnology for the Sutainability of Human Society 136S S671 - S671 2008年10月

Enhanced digetion of waste activated sludge (WAS) by thermophilic WAS-lysing bacteria 査読有り

Xuesong Li,Shoichiro Matsumoto,Qunhui Wang,Toshinari Maeda,Hiroaki I. Ogawa

Journal of Biotechnology 136S S671 - S671 2008年10月

下水余剰汚泥を溶解する細菌株の分離・同定およびその汚泥溶解性査読有り

松本翔一郎，李雪松，前田憲成，尾川博昭

環境バイオテクノロジー学会誌 8 ( 1 ) 49 - 54 2008年07月

Protein engineering of hydrogenase 3 to enhance hydrogen production 査読有り

Maeda Toshinari,Sanchez-Torres Viviana,Wood Thomas K.

Abstracts of ASM 108th General Meeting 2008年06月

Protein engineering of the transcriptional activator FhlA to enhance Escherichia coli hydrogen production 査読有り

Sanchez-Torres Viviana,Maeda Toshinari,Wood Thomas K.

Abstracts of ASM 108th General Meeting 2008年06月

Protein engineering of hydrogenase 3 to enhance hydrogen production 査読有り

Toshinari Maeda,Viviana Sanchez-Torres,Thomas K. Wood

Applied Microbiology and Biotechnology 79 ( 1 ) 77 - 86 2008年05月

Formate detection by potassium permanganate for enhanced hydrogen production in Escherichia coli 査読有り

Toshinari Maeda,Thomas K. Wood

International Journal of Hydrogen Energy 33 ( 9 ) 2409 - 2412 2008年05月

Metabolically-engineered bacteria for producing hydrogen via fermentation 査読有り

Gonul Vardar-Schala,Toshinari Maeda,Thomas K. Wood

Microbial Biotechnology 1 ( 2 ) 107 - 125 2008年03月

Metabolic engineering to enhance bacterial hydrogen production 査読有り

Toshinari Maeda,Viviana Sanchez-Torres,Thomas K. Wood

Microbial Biotechnology 1 ( 1 ) 30 - 39 2008年01月

Enhanced hydrogen production from glucose by metabolically engineered Escherichia coli 査読有り

Toshinari Maeda,Viviana Sanchez-Torres,Thomas K. Wood

Applied Microbiology and Biotechnology 77 ( 4 ) 879 - 890 2007年12月

Escherichia coli hydrogenase 3 is a reversible enzyme possessing hydrogen uptake and synthesis activities 査読有り

Toshinari Maeda,Viviana Sanchez-Torres,Thomas K. Wood

Applied Microbiology and Biotechnology 76 ( 5 ) 1035 - 1042 2007年10月

Protein engineering of the quorum-sensing regulator SdiA of Escherichia coli to control biofilm formation by controlling cell-cell communication 査読有り

Lee Jintae,Maeda Toshinari,Wood Thomas K.

Abstracts of ASM Conference on Biofilm Signaling 2007年10月

Fluorine elimination from 4-fluorobenzyl alcohol by Pseudomonas spp. 査読有り

Toshinari Maeda,Daisuke Okamura,Masaya Yokoo,Eisaku Yamashita,Hiroaki I. Ogawa

Journal of Environmental Biotechnology 7 ( 1 ) 45 - 53 2007年07月

Identification of spontaneous conversion products of unstable 2,4,6-trinitrotoluene metabolites, hydroxylamino-dinitrotoluenes, by combination of thin-layer chromatography and laser time-of-flight mass spectrometry 査読有り

Toshinari Maeda,Nobuaki Nagafuchi,Akira Kubota,Kiwao Kadokami,Hiroaki I. Ogawa

Journal of Chromatographic Science 45 ( 6 ) 345 - 349 2007年06月

Inhibition of hydrogen uptake in Escherichia coli by expressing the hydrogenase from the cyanobacterium Synechocystis sp. PCC 6803 査読有り

Toshinari Maeda,Gonul Vardar,William T. Self,Thomas K. Wood

BMC Biotechnology 7 25 - 25 2007年05月

Relationship between mutagenicity and reactivity or biodegradability for nitroaromatic compounds 査読有り

Toshinari Maeda,Ryosuke Nakamura,Kiwao Kadokami,Hiroaki I. Ogawa

Environmental Toxicology and Chemistry 26 ( 2 ) 237 - 241 2007年02月

Crucial problem in rapid spectrophotometric determination of 2,4,6-trinitrotoluene and its breakthrough method 査読有り

Toshinari Maeda,Akira Kubota,Nobuaki Nagafuchi,Kiwao Kadokami,Hiroaki I. Ogawa

Journal of Microbiological Methods 66 ( 3 ) 568 - 571 2006年09月

A cellular bioassay for TNT detection using engineered Pseudomonas sp. strain TM101 for systematic bioremediation 査読有り

Hitoshi Asakawa,Toshinari Maeda,Hiroaki I. Ogawa,Tetsuya Haruyama

Journal of Biological Physics and Chemistry 6 ( 3 ) 119 - 123 2006年09月

Facile detection method of 2,4,6-trinitrotoluene using deletion-mutant Pseudomanas sp. strain TM101 査読有り

Hitoshi Asakawa,Toshinari Maeda,Hiroaki I. Ogawa,Tetsuya Haruyama

Proceeding of the International Symposium on Environmental Biotechnology 2006 219 - 219 2006年07月

Characterization of 2,4,6-trinitrotoluene (TNT)-metabolizing bacteria isolated from TNT-polluted soils in the Yamada Green Zone, Kitakyushu, Japan 査読有り

Toshinari Maeda,Kiwao Kadokami,Hiroaki I. Ogawa

Journal of Environmental Biotechnology 6 ( 1 ) 33 - 39 2006年06月

One-step isolation and identification of hydroxylamino-dinitrotoluenes, unstable products from 2,4,6-trinitrotoluene metabolites, with thin-layer chromatography and laser time-of-flight mass spectrometry 査読有り

Toshinari Maeda,Nobuaki Nagafuchi,Akira Kubota,Kiwao Kadokami,Hiroaki I. Ogawa

Journal of Chromatographic Science 44 ( 2 ) 96 - 100 2006年02月

Regulation of homologous integration in yeast by the DNA repair proteins Ku70 and RecQ 査読有り

Yoshimasa Yamana,Toshinari Maeda,Hiroyuki Ohba,Takehiko Usui,Hiroaki I. Ogawa,kohji Kusano

Molecular Genetics and Genomics 273 ( 2 ) 167 - 176 2005年04月

シュードモナス属細菌TM15株による2,4,6-トリニトロトルエンの生分解に関する研究査読有り

前田憲成,門上希和夫,尾川博昭

Science and Technology of Energetic Materials 65 ( 3 ) 94 - 96 2004年06月

旧弾薬庫跡地土壌における2,4,6-トリントロトルエン生分解微生物のスクリーニング査読有り

前田憲成,梁明,大住幸秀,草野好司,門上希和夫,尾川博昭

環境化学 13 ( 3 ) 695 - 704 2003年09月

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