Low-potential respirators support electricity production in microbial fuel cells.

In this paper, we analyse how electric power production in microbial fuel cells (MFCs) depends on the composition of the anodic biofilm in terms of metabolic capabilities of identified sets of species. MFCs are a promising technology for organic waste treatment and sustainable bioelectricity production. Inoculated with natural communities, they present a complex microbial ecosystem with syntrophic interactions between microbes with different metabolic capabilities. Our results demonstrate that low-potential anaerobic respirators--that is those that are able to use terminal electron acceptors with a low redox potential--are important for good power production. Our results also confirm that community metabolism in MFCs with natural inoculum and fermentable feedstock is a two-stage system with fermentation followed by anode respiration.