Microbial electrosynthesis systems (MES) are promising devices in which microbes obtain electrons from electrodes to produce extracellular multicarbon compounds. This study investigates whether improvement in cell permeability can enhance electrosynthesis performance of Gram-positive Moorella thermoautotrophica in MES. Results showed that when ≤30 mg/L penicillin was added, the cell permeability was doubled, and the electron uptake per biomass (including both cathode-associated biomass and suspended biomass) was 1.84 times that of the control, while formate and acetate production rates per biomass were 1.96 and 2.23 times those of the control, respectively. Enhanced cell permeability caused higher redox activities of outmost cytochrome C and increased release of redox electron shuttles, both of which were beneficial to extracellular electron uptake. Coulombic efficiencies increased from 73% ± 3% to 88% ± 3% with better cell permeability, demonstrating that higher proportion of electrical energy recovered in the chemical-production reaction. This research demonstrates that making a moderate decrease in peptidoglycan of cell walls to improve cell permeability can enhance electron uptakes and chemical production rates of Gram-positive microbes in MES, which would serve as a base for the future genetic modification study of superior electrosynthesis strains.

微生物电合成系统（MES）是有前途的设备，其中微生物从电极获取电子以产生细胞外多碳化合物。这项研究调查细胞通透性的改善是否可以增强革兰氏阳性热自养莫尔氏菌的电合成性能在MES中。结果表明，当添加≤30mg / L青霉素时，细胞渗透率翻倍，并且每个生物量（包括阴极相关生物量和悬浮生物量）的电子吸收是对照的1.84倍，甲酸盐和乙酸盐的产生速率每个生物量分别是对照的1.96和2.23倍。增强的细胞通透性引起最外层细胞色素C的更高的氧化还原活性和氧化还原电子梭的释放增加，这两者都有助于细胞外电子的吸收。库仑效率从73％±3％增加到88％±3％，具有更好的细胞渗透性，表明化学生产反应中回收的电能比例更高。