Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Bioelectrochemistry. 2018 Jun;121:151-159. doi: 10.1016/j.bioelechem.2018.02.003. Epub 2018 Feb 8.
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 ≤30mg/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.
微生物电解合成系统（MES）是一种很有前途的装置，其中微生物可以从电极获得电子，以产生细胞外多碳化合物。本研究考察了细胞通透性的提高是否可以增强 MES 中革兰氏阳性菌 Moorella thermoautotrophica 的电合成性能。结果表明，当添加≤30mg/L 的青霉素时，细胞通透性增加了一倍，阴极相关生物量和悬浮生物量的电子摄取量分别是对照的 1.84 倍和 1.96 倍，而生物量的 formate 和 acetate 产率分别是对照的 2.23 倍和 2.23 倍。增强的细胞通透性导致最外层细胞色素 C 的氧化还原活性更高，并增加了氧化还原电子穿梭物的释放，这两者都有利于细胞外电子的摄取。库仑效率从 73%±3%提高到 88%±3%，具有更好的细胞通透性，表明更多比例的电能在化学生产反应中得到回收。本研究表明，适度降低细胞壁肽聚糖以提高细胞通透性，可以增强 MES 中革兰氏阳性微生物的电子摄取和化学产物生成率，这将为未来优良电合成菌株的遗传改造研究提供基础。
