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Bioelectrochemical regulation accelerates facultatively syntrophic proteolysis
Daisuke Sasaki1, Kengo Sasaki, Masahiko Morita
1Biotechnology Sector, Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, 1646 Abiko, Abiko-shi, Chiba 270-1194, Japan
Journal of Bioscience and Bioengineering
|March 17, 2012
Summary
Bioelectrochemical systems enhance microbial metabolism by controlling redox potential. This study shows bioelectrochemical regulation boosts hydrogenotrophic methanogen growth and methane production, accelerating proteolysis in co-cultures.
Area of Science:
- Microbiology
- Biotechnology
- Electrochemistry
Background:
- Microbial metabolism is influenced by redox potential.
- Bioelectrochemical systems offer a method to control microbial environments.
- Syntrophic interactions are crucial in many microbial communities.
Purpose of the Study:
- To investigate the impact of bioelectrochemical regulation on facultative syntrophic proteolysis.
- To assess the effect of controlled redox potential on a co-culture of Coprothermobacter proteolyticus and Methanothermobacter thermautotrophicus.
- To understand how bioelectrochemical control influences microbial growth and metabolic activity.
Main Methods:
- Construction of bioelectrochemical and non-bioelectrochemical co-cultures.
- Cultivation of Coprothermobacter proteolyticus and Methanothermobacter thermautotrophicus at 55°C with casein as the carbon source.
- Control of working electrode potential at -0.8V (vs. Ag/AgCl) in bioelectrochemical cultures.
Main Results:
- Bioelectrochemical co-cultures showed 3.6 times higher hydrogenotrophic methanogen cell density and 1.5 times higher methane production compared to non-bioelectrochemical cultures.
- Coprothermobacter sp. cell density increased by 1.3 times in bioelectrochemical co-cultures.
- Protein decomposition rates correlated with Coprothermobacter sp. cell density.
Conclusions:
- Bioelectrochemical regulation significantly enhances hydrogenotrophic methanogen activity and methane production.
- The enhanced methanogen activity accelerates facultative syntrophic proteolysis through increased hydrogen consumption.
- Controlling redox potential via bioelectrochemical systems is a viable strategy to modulate microbial consortia function.
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