MAEDA Toshinari



Associate Professor


2-4 Hibikino, Wakamatsu-ku, Kitakyushu-shi, Fukuoka

Research Fields, Keywords

Microbial Functions, Bioenergy, Microbial cell communication, bioremediation, bio-adaptation


E-mail address

Undergraduate Education 【 display / non-display

  • 2001.03   Kyushu Institute of Technology   Faculty of Engineering   Graduated   JAPAN

Post Graduate Education 【 display / non-display

  • 2006.03  Kyushu Institute of Technology  Graduate School of Life Science and Systems Engineering  Department of Biological Functions and Engineering  Doctoral Program  Completed  JAPAN

Degree 【 display / non-display

  • Kyushu Institute of Technology -  Doctor of Engineering  2006.03

Biography in Kyutech 【 display / non-display

  • 2014.04

    Kyushu Institute of TechnologyGraduate School of Life Science and Systems Engineering   Department of Biological Functions Engineering   Associate Professor  

  • 2011.10

    Kyushu Institute of TechnologyGraduate School of Life Science and Systems Engineering   Department of Biological Functions and Engineering   Associate Professor  

  • 2007.10

    Kyushu Institute of TechnologyGraduate School of Life Science and Systems Engineering   Assistant Professor  

Biography before Kyutech 【 display / non-display

  • 2006.04

    Artie McFerrin Department of Chemical Engineering, Texas A&M University   Postdoctal Researcher   UNITED STATES

Academic Society Memberships 【 display / non-display

  • 2008.04

    Japan Society on Water Environment  JAPAN

  • 2008.04

    Japan Society for Environmental Biotechnology  JAPAN

  • 2008.04

    The Society for Biotechnology, Japan  JAPAN

Specialized Field (scientific research fund) 【 display / non-display

  • Biofunction/Bioprocess

  • Environmental engineering and reduction of environmental burden

  • Applied biochemistry

  • Applied microbiology

  • Applied biochemistry


Research Career 【 display / non-display

  • Elucidation of bacterial infection by Bdellovibrio and its engineering

    Bdellovirio, bacterial infection, lytic activity  

    Project Year: 2011.04  -  Now 

  • Elucidation of microbial communication and its engineering

    quorum sensing, quorum quenching, metabolism  

    Project Year: 2011.04  -  Now 

  • Development of techniques to improve oral environment using microbial functions

    Periodontal pathogens, anti-periodontal bacteria, lytic activity, growth inhibition  

    Project Year: 2009.04  -  Now 

  • Bioenegy production using microbial functions

    Hydrogen, methane, metabolic engineering, protein engineering  

    Project Year: 2008.04  -  Now 

  • Recycle of Waste activated sludge

    Sludge reduction, recycle, utilization, microbial function  

    Project Year: 2007.10  -  Now 

Publications (Article) 【 display / non-display

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

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

    Geosciences (Switzerland)    9 ( 11 )   2019.11  [Refereed]

     View Summary

    © 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.

    repository DOI Scopus

  • Seeding Public Goods Is Essential for Maintaining Cooperation in Pseudomonas aeruginosa

    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   2019.10  [Refereed]

     View Summary

    © 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.

    repository DOI Scopus

  • Cytocompatible and antibacterial properties of chitosan-siloxane hybrid spheres

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

    Polymers    11 ( 10 )   2019.10  [Refereed]

     View Summary

    © 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 Scopus

  • Pseudogene YdfW in Escherichia coli decreases hydrogen production through nitrate respiration pathways

      44 ( 31 ) 16212 - 16223   2019.06  [Refereed]

     View Summary

    © 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 Scopus

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

      103 ( 3 ) 1485 - 1495   2019.02  [Refereed]

     View Summary

    © 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 Scopus

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Publications (Books) 【 display / non-display

  • 九工大世界トップ技術, 3

    前田憲成, 中野光一, 尾川博昭 ( Joint Work ,  執筆と編集 )

    西日本新聞社  2012.03 ISBN: 978-4-8167-0844-2

  • Microbial Degradation of Xenobiotics

    ( Joint Work )

    Springer  2011.11 ISBN: 978-3-642-23788-1

Conference Prsentations (Oral, Poster) 【 display / non-display

  • 下水汚泥のメタン発酵におけるハザードケミカルの影響

    星子 裕貴

    第70回日本生物工学会大会  (関西大学)  2018.09  -  2018.09  日本生物工学会

  • 飢餓状態における緑膿菌の生存戦略:アルカリプロテアーゼと細胞外DNAの相関性調査


    第55回化学関連支部合同九州大会・外国人研究者交流国際シンポジウム  (北九州国際会議場)  2018.06  -  2018.06 

  • 微生物群集構造解析による抗がん剤5-フルオロウラシルの汚泥中細菌叢に与える影響評価


    第55回化学関連支部合同九州大会・外国人研究者交流国際シンポジウム  (北九州国際会議場)  2018.06  -  2018.06 

  • 緑膿菌のクォーラムセンシング阻害に関わるフルオロウラシルの微生物分解経路の解明


    第55回化学関連支部合同九州大会・外国人研究者交流国際シンポジウム  (北九州国際会議場)  2018.06  -  2018.06 

  • フルオロウラシルのクォーラムセンシング阻害効果に必須な緑膿菌分解活性


    環境バイオテクノロジー学会2018年度大会  (筑波大学)  2018.06  -  2018.06  環境バイオテクノロジー学会

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Lectures 【 display / non-display

  • How can Pseudomonas aeruginosa adapt the environment of quorum quenching?

    The 2nd International Symposium: New alternatives to combat bacterial infections ( UNAM )  2017.11.10  UNAM

  • Mature biofilm degradation by Probiotic Bacteria: Aggregatibacter actinomycetemcomitans versus Lactobacillus spp.

    2017 International Meeting of the Microbiological Society of Korea ( BEXCO )  2017.04.27  Microbiological Society of Korea

  • 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

    日本農芸化学会2016年度札幌大会シンポジウム   2016.03.28 

Honors and Awards 【 display / non-display

  • Poster Awards of the 2013 Annual Meeting of Japan Society for Environmental Biotechnology

    2013.05.31     JAPAN

    Winner: Junichi Yoshimura, Toshinari Maeda

  • Poster Awards of the 2012 Annual Meeting of Japan Society for Environmental Biotechnology

    2012.06.26     JAPAN

  • Poster Awards of the 2008 Annual Meeting of Japan Society for Environmental Biotechnology

    2008.06.27     JAPAN

Contracts 【 display / non-display

  • Metabolic and protein engineering to enhance bacterial hydrogen production

    Other joint research

    Project Year:  2008.04  -  Now

Other External Funds 【 display / non-display

  • Young researchers overseas visits program for Bornean biodiversity conservation and low carbon society creation

    Project Year:  2010.10  -  2013.03

  • Enhanced bacterial hydrogen production by the utilization of microarray technology

    Project Year:  2010.03  -  2010.08


Activities of Academic societies and Committees 【 display / non-display

  • 2014.04

    Japan Society for Environmental Biotechnology  

  • 2012.09

    Japan Society for Environmental Biotechnology  

  • 2012.04

    Japan Society on Water Environment  

  • 2010.04

    Japan Society for Environmental Biotechnology