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Microbial loop, dominant food chain in lake hypolimnion

Research Project

Project/Area Number 19H03302
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Review Section Basic Section 45040:Ecology and environment-related
Research InstitutionKyoto University

Principal Investigator

Nakano Shin-ichi  京都大学, 生態学研究センター, 教授 (50270723)

Co-Investigator(Kenkyū-buntansha) 三木 健  龍谷大学, 先端理工学部, 教授 (00815508)
山口 保彦  滋賀県琵琶湖環境科学研究センター, 総合解析部門, 研究員 (50726221)
早川 和秀  滋賀県琵琶湖環境科学研究センター, 総合解析部門, 部門長 (80291178)
Project Period (FY) 2019-04-01 – 2022-03-31
Project Status Completed (Fiscal Year 2021)
Budget Amount *help
¥17,420,000 (Direct Cost: ¥13,400,000、Indirect Cost: ¥4,020,000)
Fiscal Year 2021: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2020: ¥5,720,000 (Direct Cost: ¥4,400,000、Indirect Cost: ¥1,320,000)
Fiscal Year 2019: ¥7,150,000 (Direct Cost: ¥5,500,000、Indirect Cost: ¥1,650,000)
Keywords琵琶湖 / 深水層 / 微生物ループ / CL500-11細菌 / 溶存態有機物 / 準易分解性溶存有機物 / キネトプラスチド鞭毛虫 / 溶存有機物 / 湖沼深水層 / CL500-11 / 原生生物 / 湖沼 / 細菌
Outline of Research at the Start

湖沼の深水層において、細菌による溶存有機物の利用、原生生物の摂食およびウィルスの感染による細菌の死滅までを調べ、湖沼深水層における微生物ループの動態を明らかにする。群集・ゲノム解析による細菌と原生生物の多様性と生理生態学的特性の解明、最先端測定機器による有機物化学分析による細菌餌資源の検討、海外研究者との共同による最先端技術を用いる細菌の死滅過程の定性・定量的解析を行う。これらにより、湖沼深水層の微生物ループを基軸とした「Hypolimnion ecology(湖沼深水層生態学)」を提唱し、これまで未解明な秘境生態系とも言える湖沼深水層における生態学の学術基盤を構築する。

Outline of Final Research Achievements

The aim of the present study was to establish a research foundation of ecology in the lake hypolimnion, through the elucidation of ecological processes in the hypolimnion microbial loop. We clarified that the hypolimnion bacterial assemblages (HBA), dominated by CL500-11 bacterium, convert the organic carbon supplied by sinking of phytoplankton into high molecular weight dissolved organic carbon (DOC), though it was suggested that the decomposition of DOC in the hypolimnion by HBA was not efficient. We successfully prepared the HBA genome catalog superior in quantity and quality to previous ones, and the catalog of bacterial gene expression in Lake Biwa. Further studies are necessary to collect more information about the loss processes of HBA.

Academic Significance and Societal Importance of the Research Achievements

従来、湖沼の生態学的プロセスに関する研究は、そのほとんどが太陽光が透過する光合成が活発な表水層において行われてきた。一方、湖沼の最下層で底泥を含まない深水層は、太陽光が届かず、水温も低く、生物の現存量・生産が低いために、多くの研究者の注目を受けることが無かった。深水層の生態系は、細菌や原生生物などの微生物が優占するシステムであると考えられ、本研究は深水層の生態学的プロセスの全容を解明する端緒となる。また、気候変動により湖沼深水層の貧酸素化が懸念される現在、本研究は地球環境問題に対しても重要な情報を提供する。

Report

(4 results)
  • 2021 Annual Research Report   Final Research Report ( PDF )
  • 2020 Annual Research Report
  • 2019 Annual Research Report
  • Research Products

    (24 results)

All 2021 2020 2019 Other

All Int'l Joint Research (3 results) Journal Article (5 results) (of which Peer Reviewed: 5 results,  Open Access: 1 results) Presentation (16 results) (of which Int'l Joint Research: 7 results,  Invited: 2 results)

  • [Int'l Joint Research] チェコ科学アカデミー・水生生物研究所(チェコ)

    • Related Report
      2021 Annual Research Report
  • [Int'l Joint Research] チェコ科学アカデミー・水生生物研究所(チェコ)

    • Related Report
      2020 Annual Research Report
  • [Int'l Joint Research] チェコ科学アカデミー・水生生物研究所(チェコ)

    • Related Report
      2019 Annual Research Report
  • [Journal Article] Application of image analysis for algal biomass quantification: a low-cost and non-destructive method based on HSI color space2021

    • Author(s)
      Jiang, M., S. Nakano
    • Journal Title

      Journal of Applied Phycology

      Volume: 33 Issue: 6 Pages: 3709-3717

    • DOI

      10.1007/s10811-021-02571-4

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Phylogenetic diversity of the picocyanobacterial community from a novel winter bloom in Lake Biwa2021

    • Author(s)
      Cai, J., Y. Hodoki, S. Nakano
    • Journal Title

      Limnology

      Volume: 22 Issue: 2 Pages: 161-167

    • DOI

      10.1007/s10201-020-00649-5

    • NAID

      40022532743

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Influence of potential grazers on picocyanobacterial abundance in Lake Biwa revealed with empirical dynamic modeling2020

    • Author(s)
      Cai, J., Y. Hodoki, M. Ushio, S. Nakano
    • Journal Title

      Inland Waters

      Volume: 10 Issue: 3 Pages: 386-396

    • DOI

      10.1080/20442041.2020.1711682

    • NAID

      120007184435

    • Related Report
      2020 Annual Research Report 2019 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Genome‐resolved viral and cellular metagenomes revealed potential key virus‐host interactions in a deep freshwater lake2019

    • Author(s)
      Okazaki Yusuke、Nishimura Yosuke、Yoshida Takashi、Ogata Hiroyuki、Nakano Shin‐ichi
    • Journal Title

      Environmental Microbiology

      Volume: 21 Issue: 12 Pages: 4740-4754

    • DOI

      10.1111/1462-2920.14816

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Widespread dominance of kinetoplastids and unexpected presence of diplonemids in deep freshwater lakes.2019

    • Author(s)
      Mukherjee I, Hodoki Y, Okazaki Y, Fujinaga S, Ohbayashi K, Nakano S.
    • Journal Title

      Frontiers in Microbiology

      Volume: 10 Pages: 2375-2375

    • DOI

      10.3389/fmicb.2019.02375

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed / Open Access
  • [Presentation] Long term research in Lake Biwa with special reference to global climate change2021

    • Author(s)
      Shin-ichi Nakano
    • Organizer
      9th Congress of the East Asian Federation of Ecological Societies
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research
  • [Presentation] A Unique Microbial Loop in the Hypolimnion of Lake Biwa2021

    • Author(s)
      Shin-ichi Nakano
    • Organizer
      35th Congress of the International Society of Limnology
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] 湖と河川における溶存有機物の分子サイズ別の生分解速度2021

    • Author(s)
      山口保彦, 霜鳥孝一, 今井章雄, 岡崎友輔, 尾原禎幸, 中村光穂, 七里将一, 岡本高弘, 早川和秀
    • Organizer
      日本地球惑星科学連合2021年大会(オンライン開催)
    • Related Report
      2021 Annual Research Report
  • [Presentation] Biodegradation kinetics and molecular-size distribution of freshwater dissolved organic matter during long-term incubations2021

    • Author(s)
      Yamaguchi, Y. T., Shimotori, K., Imai, A., Okazaki, Y., Ohara, T., Nakamura, M., Hichiri, S., Okamoto, T., and Hayakawa K.
    • Organizer
      ASLO 2021 Aquatic Sciences Meeting(オンライン開催)
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Biodegradation kinetics of different molecular-size classes of freshwater dissolved organic matter during long-term incubations2021

    • Author(s)
      Yamaguchi, Y. T., Shimotori, K., Imai, A., Okazaki, Y., Ohara, T., Nakamura, M., Hichiri, S., Okamoto, T., and Hayakawa K.
    • Organizer
      SIL 2021: 35th Congress of the International Society of Limnology(オンライン開催)
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research
  • [Presentation] 琵琶湖の水質と生態系の保全にかかる有機物循環の解析:溶存有機物の分子サイズ別分解速度と湖内物質循環への寄与2021

    • Author(s)
      山口保彦, 霜鳥孝一, 今井章雄, 岡崎友輔, 尾原禎幸, 中村光穂, 七里将一, 岡本高弘, 早川和秀
    • Organizer
      2021年度日本腐植物質学会第37回講演会(オンライン開催)
    • Related Report
      2021 Annual Research Report
  • [Presentation] 水圏溶存有機物のサイズ反応性連続体モデルを再考する2021

    • Author(s)
      山口保彦
    • Organizer
      第38回有機地球化学シンポジウム(オンライン&札幌)
    • Related Report
      2021 Annual Research Report
  • [Presentation] Ecogenomics of bacteria and viruses in the water column of Lake Biwa2021

    • Author(s)
      Okazaki, Y.
    • Organizer
      SIL 2021: 35th Congress of the International Society of Limnology(オンライン開催)
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research
  • [Presentation] ロングリード解析で拓くメタゲノムビニングの限界と環境細菌ゲノムの微小多様性2021

    • Author(s)
      岡崎友輔, 中野伸一, 豊田敦, 玉木秀幸
    • Organizer
      微生物生態学会第34回大会 (2021.10, オンライン開催)
    • Related Report
      2021 Annual Research Report
  • [Presentation] 湖内および湖間の細菌のゲノム多様性の解明2021

    • Author(s)
      岡崎友輔, 藤永承平, 田中敦, 高津文人, 大八木英夫, 中野伸一
    • Organizer
      日本陸水学会第85回大会 (2021.9, オンライン開催)
    • Related Report
      2021 Annual Research Report
  • [Presentation] Macroscale vertical power-law distribution of bacteria in dark oceans can emerge from microscale bacteria-particle interactions2021

    • Author(s)
      Takeshi MIKI, Po-Ju KE
    • Organizer
      日本生態学会第68回全国大会
    • Related Report
      2020 Annual Research Report
  • [Presentation] Distribution of “minor” amino acids enantiomers in dissolved organic matter in marine vs. inland waters2020

    • Author(s)
      Yamaguchi, Y. T., McCarthy M. D., Yoshimizu C., Tayasu I., Koba K., and Hayakawa K.
    • Organizer
      Goldschmidt2020
    • Related Report
      2020 Annual Research Report
    • Int'l Joint Research
  • [Presentation] 細菌由来の準易分解性溶存有機窒素が水圏の栄養塩供給経路となる可能性について2020

    • Author(s)
      山口保彦
    • Organizer
      2020年度日本地球化学会第67回年会
    • Related Report
      2020 Annual Research Report
  • [Presentation] Major modelling approaches that are useful to environmental microbiology: their applicability and limitations2020

    • Author(s)
      Takeshi Miki
    • Organizer
      チリ微生物学会シンポジウム (Congreso SoMiCh 2020)
    • Related Report
      2020 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] 大水深湖に生息する細菌の系統地理的パターンの解明2019

    • Author(s)
      岡崎友輔, 藤永承平, 田中敦, 高津文人, 大八木英夫, 中野伸一
    • Organizer
      日本陸水学会第84回大会
    • Related Report
      2019 Annual Research Report
  • [Presentation] メタゲノム解析による湖水中のファージの多様性と生態の解明2019

    • Author(s)
      岡崎友輔, 西村陽介, 吉田天士, 緒方博之, 中野伸一
    • Organizer
      日本微生物生態学会第33 回大会
    • Related Report
      2019 Annual Research Report

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Published: 2019-04-18   Modified: 2023-01-30  

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