Ibaraki University's
Ibaraki University

Vice President

OHTA Hiroyuki

  • Birth:1954


  1. Tohoku University Institute for Agricultural Research Postdoctoral fellow, Japan Promotion of Science 1982/04/01-1984/03/31
  2. Okayama University Dental School Assistant Professor 1984/04/01-1992/05/31
  3. Okayama University Dental School Associtae Professor 1992/06/01-1997/07/31
  4. Ibaraki University College of Agriculture Associtae Professor 1997/08/01-2002/05/31
  5. Ibaraki University College of Agriculture Professor 2002/06/01-Present
  6. Ibaraki University Vice President 2014/09/01-2016/03/31
  7. Ibaraki University Director, Vice President (Education) 2016/04/01-Present

Academic background

  1. Tohoku University Faculty of Agriculture 農芸化学 1977 Graduated
  2. Tohoku University Graduate School, Division of Agriculture 農芸化学 Doctor course 1982 Completed

Academic degrees

  1. Doctor of Agricultural Science Tohoku University
  2. Master of Agricultural Science Tohoku University

Current state of research and teaching activities


Research Areas

  1. Environmental Dynamic Analysis
  2. Environmental Influence Valuation/Environment Policy
  3. Plant Nutrient Science/Soil Studies

Research keywords

  1. Microbial Ecology, Environmental Chemistry and Toxicology, Microbial Physiology, Bacterial Taxonomy

Subject of research

  1. Taxonomy and genetic analysis of soil oligotrophic bacteria 1998-Present
  2. Microbial community analysis of young volcanic ash 1998-Present
  3. Molecular Ecology of Nonylphenol-degrading bacteria 2000-Present
  4. Microbial ecology of sclerotium grains in foreast soils 2001-Present
  5. Analysis of microbial ecosystem structure and development in the space environment and Martian analogs 2004-Present
  6. Ecology and physiology of nitrous oxide-producing microbes in upland soils 畑地に分布する糸状菌の亜酸化窒素発生活性とその発生メカニズムを解析している 2005/04-Present
  7. Global change adaptation science 2006-Present
  8. スイートソルガムを用いたバイオブタノール生産に関する研究


  1. 農学が世界を救う! 食料・生命・環境をめぐる科学の挑戦 生源寺眞一 、太田寛行、安田弘法 岩波ジュニア新書 2017/10/20 9784005008612
  2. 難培養微生物研究の最前線III 太田寛行、佐藤嘉則、西澤智康 シーエムシー出版 2015/08/07 本章の前半では,筆者らが行ってきた「内生細菌の検出方法」を紹介し,次に,これまでに報告されてきた「内生細菌の系統」を概観する。後半では,2つの糸状菌-内生細菌の関係に焦点をあて,それらの研究の進展を概説し今後の展望について述べる。
  3. 微生物の地球化学 太田寛行、難波謙二、諏訪裕一、片山葉子 東海大学出版部 2015/06/30 978-4-486-02070-7
  4. 農学入門-食料・生命・環境科学の魅力- 太田寛行・成澤才彦 養賢堂 2013/09/20 978-4-8425-0519-0
  5. Establishing a Resource-Circulating Society in Asia: Challenges and Opportunities Niita, Y., H. Ohta, and T. Kato United Nations University Press 2011 978-92-808-1184-1


  1. Research paper (scientific journal) Joint Comparative characterization of bacterial communities in moss-covered and unvegetated volcanic deposits of Mount Merapi, Indonesia Annisa N. Lathifah, Yong Guo, Nobuo Sakagami, Wataru Suda, Masanobu Higuchi, Tomoyasu Nishizawa, Irfan D. Prijambada, Hiroyuki Ohta Microbes and Environments Japan Society of Microbial Ecology 34/ 3 2019 Microbial colonization, followed by succession, on newly exposed volcanic substrates represents the beginning of an early ecosystem development. During early succession, colonization by mosses or plants significantly alters the pioneer microbial community composition through the photosynthetic carbon input. To provide more insight into this process, we investigated the three-year-old volcanic deposits of Mount Merapi, Indonesia.
  2. Research paper (scientific journal) Joint Comparative analysis of the genetic basis of branched nonylphenol degradation by Sphingobium amiense DSM 16289T and Sphingobium cloacae JCM 10874T 122. Ootsuka, M., T. Nishizawa, M. Hasegawa, Y. Kurusu, H. Ohta Microbes and Environments 33, 450-454 2018 1347-4405 10.1264/jsme2.ME18077 Branched nonylphenol (BNP), a degradation product of nonylphenol polyethoxylates, exerts estrogenic effects on various organisms. The genes underlying BNP degradation by Sphingobium amiense DSM 16289T were analyzed by complete genome sequencing and compared with those of the versatile BNP-degrading Sphingobium cloacae JCM 10874T.
  3. Research paper (scientific journal) Joint Phylogenetic characterization of viable but-not-yet cultured Legionella groups grown in amoebic cocultures: a case study using various cooling tower water samples Hiroaki Inoue , Kunio Agata, Hiroyuki Ohta Biocontrol Science The Society for Antibacterial and Antifungal Agents, Japan 23/ , in press 2018 1884-0205 Legionella spp. exist naturally in association with amoeba in water environments and are known to be the etiological agent of a severe form of pneumonia. To detect diverse Legionella populations in cooling tower water systems, the amoebic coculturing was performed for 15 water samples obtained form five different kind facilities in six geographically different locations.
  4. Research paper (scientific journal) Joint Complete genome sequence of Agrobacterium pusense VsBac-Y9, a bacterial symbiont of the dark septate endophytic fungus Veronaeopsis simplex Y34 with potential for improving fungal colonization in roots Yong Guo, Yuuto Matsuoka, Takamasa Miura, Tomoyasu Nishizawa, Hiroyuki Ohta, Kazuhiko Narisa Journal of Biotechnology 284, 31-36 2018/08/02 0168-1656 A Rhizobium-related bacterium (Rhizobium sp. VsBac-Y9) is a symbiont living with the dark septate endophytic (DSE) fungus Veronaeopsis simplex Y34. Co-inoculation of Rhizobium sp. VsBac-Y9 with V. simplex Y34 improves the fungal colonization of tomato roots, resulting in a significant increase in aboveground biomass. This study sequenced the complete genome of this V. simplex-helper bacterium using the PacBio and Illumina MiSeq platforms.
  5. Research paper (scientific journal) Joint Mortierella sugadairana, a new homothallic species related to the firstly described heterothallic species in the genus Yusuke Takashima, Yousuke Degawa, Hiroyuki Ohta, Kazuhiko Narisawa Mycoscience Elsevier B.V. 59/ 3, 200-205 2018/05 10.1016/j.myc.2017.10.004 A new species, Mortierella sugadairana, is described for a fungus forming homothallic zygospores with a club-shaped macrosuspensor and a microsuspensor originating from the macrosuspensor. The species was isolated from cool regions in Japan and morphologically and phylogenetically close to a heterothallic species M. parvispora, which is the first species reported as a heterothallic species in the genus. Mycelial growth of the species was limited at 30 °C, whereas two isolates of M. parvispora can grow. This may indicate that the species and M. parvispora adapted to different climates from a common ancestor involving differentiation of the manner of reproduction.

Research presentations

  1. Poster presentation Molecular Analysis of Microbial Community in Water Stable Aggregation of Upland Field Soils Managed by No-tillage Practices for Seven Years XVII International Colloquium on Soil Zoology 2016/08/24 Agricultural soil management practices by no-tillage and cover-cropping improve the formation of soil aggregate structures and provide storage space of nutrients that can be utilized by soil microbes. The objective of the present study was to assess the effects of tillage/no-tillage management for seven years on soil microbial diversity and its community dynamics in upland fields. In addition, we examined that the aggregate formation correlates with soil microbes in no-tilled soils.
  2. Poster presentation Microbial community structure analysis of water-stable soil aggregates in no-till cropping systems XVII International Colloquium on Soil Zoology 2016/08/24 There are increasing concerns for no-till cropping systems because they can lead to soil carbon sequestration to mitigate climate change. The potential for carbon sequestration in no-tilled soils is related to the content of water-stable aggregates (WSAs) which can constitute stable environments for microbes and organic matter. However, from the microbiological aspect, such WSAs are not yet fully characterized. This study aimed to analyze microbial communities of WSAs in relation to crop field managements. Our study sites were established in no-tilled and tilled soybean plots of the Andosol field maintained since 2003.
  3. Oral presentation(general) 不耕起栽培畑地土壌における耐水性団粒内の微生物群集構造解析 日本土壌微生物学会2016年度大会 2016/06/12 耕起による土壌の攪乱や大型機械の導入は,不耕起の場合と比べると土壌の物理性等に大きな違いが生じていると考えられる.特に,土壌団粒の発達への影響は大きいと推察される.先行研究では,耕起/不耕起や冬期カバークロップ栽培の有無等の農地土壌管理の違いが土壌微生物群集構造に与える影響を評価してきた.本研究では,耕起および不耕起栽培畑地土壌において,耐水性団粒のサイズ組成及び団粒スケールでの微生物群集構造の違いを明らかにすることを目的とした.
  4. Poster presentation Genome analysis of a DSE-commensal bacterium Rhizobium sp. Y9 associated with Veronaeopsis simplex Y34 日本土壌微生物学会2016年度大会 2016/06/11 A dark septate endophytic fungus, Veronaeopsis simplex Y34, was evaluated for many benefits to its host plant, such as suppression of soil born diseases, promotion of growth, and enhancement of resistance to environmental stresses. Interestingly, previous studies have indicated the presence of commensal bacteria living outside and inside mycelium of V. simplex Y34, and these bacteria probably affected the host-beneficial performance. One isolate of the commensal bacterium, Rhizobium sp. Y9 was successfully isolated from the community inhabiting the mycelium of the fungus. To unravel the role commensal bacteria in such triadic symbiosis, this study sequenced the whole genome of Rhizobium sp. Y9 and compared the genomic information with those of close related bacterium species.
  5. Poster presentation Mortierella属糸状菌に内生する細菌の多様性解析 日本土壌微生物学会2016年度大会 2016/06/11 微生物間で細胞内共生の関係があることが提起され、糸状菌ー内生細菌の関係では、アーバスキュラー菌根菌Gigaspora margaritaとその内生細菌Candidatus Glomeribacter gigasporum、イネ苗立枯病菌Rhizopus microsporusとリゾキシン産生内生細菌Burkholderia rhizoxinicaで詳しく研究されてきた。本研究では、我々が先に報告した新たな糸状菌ー内生細菌ペアーであるMoriterella elongataーMycoavidus cysteinexigens以外のMoriterella属糸状菌における内生細菌の分布と多様性を解析した。


  1. Udayana Award 2016/09/29 Regarding to Ohta's effort and great contribution in promoting and strengthening the cooperation between the University of Udayana and Ibaraki University, Ohta has been chosen to receive the University of Udayana Award of 2016.
  2. 第59回日本土壌肥料学会賞 土壌細菌の分類および群集解析に関する研究 2014/09/10
  3. 特別研究員等審査会専門委員(書面担当) 表彰 2013/07/31
  4. JSME Prize 2010 for the best publication Nitrogenase activity (Acetylene Reduction) of an Iron-Oxidizing Leptospirillum Strain Cultured as a Pioneer Microbe from a Recent Volcanic Deposit on Miyake-jima, Japan 2010/11/25 The authors were awarded in recognition of excellence in form, and content of the authors' paper published in Microbes and Environments, volume 24, 2009.
  5. 両備(]J3727[)園記念財団研究助成 1993

Alloted class

  1. Advanced Environmental Toxicology and Chemistry
  2. Analytical Chemistry
  3. Fundamentals of Soil Science
  4. Environmental chemistry and toxicology
  5. Overview of agricultural science toward regional sustainability

Memberships of academic societies

  1. 日本土壌微生物学会
  2. International Society of Microbial Ecology
  3. American Society for Microbiology
  4. The Society for General Microbiology
  5. 日本農芸化学会

Committee Career

  1. Japanese Society for Soil Microbiology 評議員 2010/01/01-2012/12/31
  2. International Society for Environmental Biogeochemistry International Committee 2009-2013
  3. 日本土壌微生物学会 評議員 2007/06-2013/05
  4. Japanese Society for Soil Microbiology 学会誌編集委員 2005/01-2008/12
  5. Japanese Society for Soil Microbiology 評議員 2005/01-2008/12