Bacteria can live in symbiosis, both in natural communities and artificial co-culture systems. The coculturing promotes substrate utilization by serving the metabolites of one community to the neighboring community for their growth . Here we developed an artificial co-culture system using G. sulfurreducens and I. sakaiensis. G. sulfurreducens usually live with fermenting communities as they grow with acetate, one of the end products of fermentation. G. sulfurreducens is a gram-negative, anaerobic, dissimilatory metal reducing bacterium with the highest electricity producing capacity in microbial fuel cells. G. sulfurreducens can transport metabolically generated electrons via acetate oxidation to a poised electrode through an extracellular electron transfer (EET) respiratory pathway . They also produce conductive protein nanowires for transporting metabolically generated electrons to insoluble electron acceptors such as metal oxide and metal electrodes .