s13068 022 02180 4

Abstract

Background: Microbial electricity production has received considerable attention from researchers due to its environmental friendliness and low price. The increase in the number of intracellular electrons in a microbial fuel cell (MFC) helps to improve the MFC performance. Results: In this study, we accumulated excess electrons intracellularly by knocking out the gene related to intracellu- lar electron consumption in Saccharomyces cerevisiae, and the elevated intracellular electron pool positively influ- enced the performances of MFCs in terms of electricity production, while helping to increase ethanol production and achieve ethanol and electricity co-production, which in turn improved the utilization of substrates. The final knockout strain reached a maximum ethanol yield of 7.71 g/L and a maximum power density of 240 mW/m² in the MFC, which was 12 times higher than that of the control bacteria, with a 17.3% increase in energy utilization. Conclusions: The knockdown of intracellular electron-consuming genes reported here allowed the accumulation of excess electrons in cells, and the elevated intracellular electron pool positively influenced the electrical produc- tion performance of the MFC. Furthermore, by knocking out the intracellular metabolic pathway, the yield of ethanol could be increased, and co-production of ethanol and electricity could be achieved. Thus, the MFC improved the utilization of the substrate.

Key findings

• ▸Maximum ethanol yield of 7.71 g/L achieved
• ▸Maximum power density of 240 mW/m² in MFC, 12 times higher than control
• ▸17.3% increase in energy utilization

Keywords

Identifiers

Journal

National Energy

Year

2019