Electrochemical control of redox potential affects methanogenesis of the hydrogenotrophic methanogen Methanothermobacter thermautotrophicus |
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Authors: | S Hirano N Matsumoto M Morita K Sasaki N Ohmura |
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Institution: | 1. Biotechnology Sector, Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, , Abiko, Japan;2. Organization of Advanced Science and Technology, Kobe University, , Noda, Kobe, Japan |
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Abstract: | To investigate the precise effect of the redox potential on the methanogenesis of the hydrogenotrophic methanogen Methanothermobacter thermautotrophicus by using an electrochemical redox controlling system without adding oxidizing or reducing agents. A bioelectrochemical system was applied to control the redox conditions in culture and to measure the methane‐producing activity of M. thermautotrophicus at a constant potential from +0·2 to ?0·8 V (vs Ag/AgCl). Methane production and growth of M. thermautotrophicus were 1·6 and 3·5 times increased at ?0·8 V, compared with control experiments without electrolysis, respectively, while methanogenesis was suppressed between +0·2 and ?0·2 V. A clear relationship between an electrochemically regulated redox potential and methanogenesis was revealed. Significance and Impact of the Study A novel bioelectrochemical method can activate the methanogenesis of M. thermautotrophicus by controlling the redox potential in culture conditions at ?0·8 V, which is a difficult potential to achieve by conventional methods (e.g. by adding reducing agents). This study provides useful insights for the application of a bioelectrochemical system in industrial processes involving methanogens, such as in anaerobic digesters. |
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Keywords: | bioproducts biotechnology metabolism microbial physiology |
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