Relation between electron balance and the methane - producing bacterial community
Electron exchange,such as interspecies hydrogen or formate transfer, occurs in methanogenic systems ( Stans and Plugge 2009; McInerney et al.2009(. A variety of organic compounds can be reduced to produce hydrogen and/ or formats,which the methanogens consume. Methanogens have been reported to be able to accept electron directly in aggregates ( Morita et al.2011). Therefore, a direct or indirect electron transfer between microorganisms is essential for methane production. Disrupting the electron balance in methanogenic systems by using microbial fuel cells (MFCs) ( Jung and Regan 2011) or a bike left to chemical reactor ( HER)(FIG.2)(sasaki et al.2010c) has been shown to influence methane production