Improving the extracellular electron transfer of Shewanella oneidensis MR-1 for enhanced bioelectricity production from biomass hydrolysate

Abstract

Direct electricity production from biomass hydrolysate by microbial fuel cells (MFC) holds great promise for the development of the sustainable biomass industry. Shewanella oneidensis MR-1 is one of the most extensively studied model exoelectrogens in MFC. But it is still unclear whether this model strain could generate bioelectricity from biomass or not. Here, a biomass hydrolysate MFC was constructed by using S. oneidensis MR-1 and electricity output was obtained from corn straw hydrolysate. More impressively, by promoting the extracellular electron transfer efficiency with electron shuttle addition and electrode modification using the vertically aligned polyaniline (PANI) nanowire array, the electricity output from biomass hydrolystate by S. oneidensis MR-1 was greatly improved and a high energy output was obtained, i.e., ∼1260 mA m⁻² current output (∼7-fold increase over that of the control) and ∼660 mW m⁻² power output (∼37-fold increase over that of the control) were achieved. This work demonstrates that S. oneidensis MR-1 has great potential in electrical energy harvesting from biomass hydrolysate, which broadens the fuel spectrum of the model exoelectrogen (S. oneidensis MR-1) inoculated MFC and also provides a new opportunity for the biomass industry.