Bioelectrochemical production of valuable products from CO2 in a microbial electrolysis cell

2016 Fiscal Year Final Research Report

• Project/Area Number: 15H06906
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Biofunction/Bioprocess
• Research Institution: Japan Agency for Marine-Earth Science and Technology
• Principal Investigator: Ishii Shunichi 国立研究開発法人海洋研究開発機構, 海底資源研究開発センター, 研究員 (10556913)
• Project Period (FY): 2015-08-28 – 2017-03-31
• Keywords: 微生物電解セル / 菌体外電子移動 / バイオカソード / 微生物電気合成 / 電極酸化メタン菌 / 微生物群集構造解析 / メタゲノム

Outline of Final Research Achievements

In this study, we operated a microbial electrolysis cell (MEC) for the stimulation and acceleration of microbial methanogenesis via voltage input to fix CO2 to valuable compounds such as methane. A MEC system was operated for 11 months where 600 mV of voltage was applied between anode and cathode, resulting in a successful conversion of CO2 to methane with electrical current consumption. The 16S rRNA-based community analyses revealed that genera Methanocalculus and Methanobacterium were located in the electromethanogenic cathode, while genus Geoalkalibacter was shown in the electrode-respiring anode. The metagenomic analysis revealed that the Geoalkalibacter genome coded numerous numbers of multi-heme c-type cytochromes, whereas methanogenic archaeal genomes contained many hydrogenases. These results suggest that direct electron transfer via cytochromes occurred on the anode, and hydrogen-mediated electron transfer functioned on the cathode.

Free Research Field

工学　（生物機能・バイオプロセス）