Novel microbial metabolism responsible for the carbon flux in deep subseafloor sediments as revealed by isolation and stable isotope probing

2018 Fiscal Year Final Research Report

• Project/Area Number: 16H05886
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Environmental dynamic analysis
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: Hori Tomoyuki 国立研究開発法人産業技術総合研究所, エネルギー・環境領域, 主任研究員 (20509533)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 環境分析 / 深海環境 / 地球化学 / 環境 / 微生物

Outline of Final Research Achievements

In this study, the anaerobically methane-oxidizing and acetate-oxidizing iron reducers were enriched from 15 different deep subseafloor core sediments with crystalline iron oxides as electron acceptors. The enrichment process was monitored by high-throughput sequencing. The obtained enrichment cultures were transferred to energetically favorable media including soluble Fe(III) or the other electron acceptors, resulting in the successful isolation of two species of the iron-reducing Firmicutes bacteria. This indicates that the acetate-oxidizing crystalline iron(III) reducers were responsible for the carbon flux in the deep subseafloor sediments.

Free Research Field

環境微生物学

Academic Significance and Societal Importance of the Research Achievements

本研究で標的とする炭素化合物「メタンおよび酢酸」と地球第４位の構成元素「鉄」は地球上最大の根源物質であるため、その代謝に関わる未知微生物群の実体解明は、地下圏の生命活動全体を紐解くことに直結する。陸域土壌からよく検出されるDeltaproteobacteria綱に属する鉄還元・酢酸酸化菌が地下深部からは取得されなかったことから、海底下では陸上圏とは異なる結晶性酸化鉄の還元機構が存在していることが強く示唆された。