Microbial electrosynthesis (MES) is potentially useful for the biological conversion of carbon dioxide into value-added chemicals and biofuels. The study evaluated several limiting factors that affect MES performance. Among all these factors, the optimization of the applied cell voltage, electrode spacing, and trace elements in catholytes may significantly improve the MES performance. MES was operated under the optimal condition with an applied cell voltage of 3 V, an electrode spacing of 8 cm, 2× salt solution, and 8× trace element of catholyte for 100 days, and the maximum acetate concentration reached 7.8 g L⁻¹. The microbial community analyses of the cathode chamber over time showed that Acetobacterium, Enterobacteriaceae, Arcobacter, Sulfurospirillum, and Thioclava were the predominant genera during the entire MES process. The abundance of Acetobacterium first increased and then decreased, which was consistent with that of acetate production. These results provided useful hints for replacing the potentiostatic control of the cathodes in the future construction and operation of MES. Such results might also contribute to the practical operation of MES in large-scale systems.

中文翻译：

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直流电系统通过微生物电合成还原CO 2驱动乙酸产生乙酸的影响因素的实验评估

微生物电合成（MES）对于将二氧化碳生物转化为增值化学品和生物燃料很有用。该研究评估了影响MES性能的几个限制因素。在所有这些因素中，施加的电池电压，电极间距和阴极电解液中痕量元素的优化可以显着提高MES性能。MES在最佳条件下操作，施加3 V电池电压，8 cm电极间距，2x盐溶液和8x阴极电解质微量元素100天，最大乙酸盐浓度达到7.8 g L ^-1。随着时间的推移，阴极室的微生物群落分析表明，醋杆菌，肠杆菌科，芽孢杆菌在整个MES过程中，磺脲类，硫磺螺菌属和硫噻唑属是最主要的属。醋杆菌的丰度先增加然后减少，这与乙酸盐的产生是一致的。这些结果为将来在MES的构建和运行中替代阴极的恒电位控制提供了有用的提示。这些结果也可能有助于大规模系统中MES的实际操作。