Dynamics and adaptations of the microbiome in methane fermentation in response to organic load shocks

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K17906
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 64020:Environmental load reduction and remediation-related
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Koyama Mitsuhiko 東京工業大学, 環境・社会理工学院, 助教 (50794038)
• Project Period (FY): 2021-04-01 – 2023-03-31
• Keywords: メタン発酵 / 有機物負荷ショック / 微生物叢 / 微生物ネットワーク

Outline of Final Research Achievements

This study aimed to elucidate the response and adaptation of the methane fermentation microbial community to repeated loading shocks to develop a resilient system for methane fermentation to organic loading shocks. It was found that inoculum acclimated to complex substrates showed greater resilience to loading shocks, as microbial diversity was stable and methane yield was less affected, even at high organic loadings. On the other hand, less frequent loading shocks severely disrupted the microbial network structure and ultimately impacted methane productivity. We therefore inoculated the seedlings acclimated to higher organic loadings and found that methane productivity was maintained and the microbial network was stable, even after repeated load shocks.

Free Research Field

環境生物工学

Academic Significance and Societal Importance of the Research Achievements

従来、メタン発酵技術は処理対象が通年定量排出されることから、一定の有機物負荷条件においてプロセスの高効率化やメカニズムの解明が取り組まれてきた。一方で近年増加傾向の「突発的に発生する有機性固形廃棄物」へのメタン発酵の応用が考えられるが、負荷変動がメタン発酵の安定性に及ぼす影響に関する知見は乏しい。本研究は、負荷変動に対するメタン発酵の動態と安定化を初めて明らかにしたものである。変動に強い装置は、すなわち安全係数の低い小型装置を作ることができるようになるため、メタン発酵技術を、供給量の日変動が大きい小規模装置が望まれる過疎地域や船舶、果ては宇宙船などにも導入できるようになることが期待される。