研究者詳細 - 前田　憲成

論文 - 前田　憲成

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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）

<p>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.</p>

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）

<p>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.</p>

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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その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85101522464&origin=inward

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