Elucidation of hydrogen production mechanisms from succinate oxidation in a thermophilic propionate oxidizing bacterium

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K07666
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Applied microbiology
• Research Institution: Yamaguchi University
• Principal Investigator: Kosaka Tomoyuki 山口大学, 大学院創成科学研究科, 助教 (70500453)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 共生的プロピオン酸酸化 / メタン発酵 / コハク酸脱水素酵素 / フマル酸還元酵素 / プロピオン酸酸化細菌 / 水素生成 / 膜電位

Outline of Final Research Achievements

The revealed factors required for hydrogen production from propionate in Pelotomaculum thermopropionicum were membrane potential, ATP synthetase, and quinones. On the other hand, the two succinate dehydrogenases found in the genome of P. thermopropionicum proposed as responsible for succinate oxidation in the propionate metabolism, of which membrane binding SDH1 was proposed the major succinate dehydrogenase under a propionate oxidizing condition, whereas cytoplasmic SDH2 was predicted as a fumarate reductase under a non-propionate oxidizing condition. These results suggest that protein components localized in membrane responsible for the succinate oxidation are important for the propionate metabolism in P. thermopropionicum.

Free Research Field

応用微生物学

Academic Significance and Societal Importance of the Research Achievements

高温メタン発酵ではプロピオン酸などの有機酸が蓄積しやすく、その代謝に重要な因子の探索は高温メタン発酵の安定化につながることが期待される。今回の研究成果によって、中温の場合と同様に高温メタン発酵においてもプロピオン酸酸化には細胞の膜電位が重要であることが示されたことから、メタン発酵槽への微生物の膜電位に影響を及ぼす化学物質の混入やそれらを生産する微生物の増殖がメタン発酵槽の不安定化を引き起こすことが示唆された。