Increasing intracellular releasable electrons dramatically enhances bioelectricity output in microbial fuel cells

Microbial fuel cell (MFC) is a sustainable energy source that can harvest electricity energy from organic wastes. However, its low electricity output remains the bottleneck for practical applications. Herein, we report a novel approach to increase extracellular electron transfer between bacteria and anodes, thus enormously enhancing the bioelectricity output in MFCs. We find that the abolishment of the lactate synthesis pathway increases intracellular releasable electrons, which are subsequently transferred to the anode via a secreted diffusive electron shuttle. Thereby, such genetically modified strain delivers a much higher and more stable electricity output than its parental strain in MFCs.

Graphical abstractA novel approach to burst bioelectricity power output of microbial fuel cells: redirecting releasable intracellular electrons in E. coli to the anode by eliminating the lactate synthesis pathway.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Abolish of lactate synthesis redirects intracellular electrons to anode. ► Deletion of lactate synthesis pathway delivers much higher electricity. ► An electron shuttle helps to establish efficient extracellular electron transfer.