Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China.
Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China.
Bioresour Technol. 2020 Aug;309:123322. doi: 10.1016/j.biortech.2020.123322. Epub 2020 Apr 6.
Extracellular electron transfer (EET) is a significant pathway to transport electrons between bacteria and electrode in microbial electrosynthesis systems (MESs). To enhance EET in the MES, a high-conductivity polymer, polypyrrole (PPy), was coated on the surface of mixed culture acetogens in situ and the PPy-coated bacteria were inoculated on the cathode of MES. The charge transfer resistance of PPy-coated biocathode was 33%-70% of that with PPy-uncoated. Acetate production rate and Faradic efficiency in PPy-coated biocathodes increased by 3 to 6 times. After 960 h operation, Acetobacterium, Desulfovibrio, and Acinetobacter dominate the community on the coated and uncoated biocathode. Quinone loop and NADH dehydrogenase to ubiquinone were involved in electron transfer pathway of biocathode and stimulated by PPy coating. Low-level expression of C-type cytochromes on biocathode indicated its less important role in inward EET. The study provided useful information for applications of high-conductivity chemicals in microbial electrosynthesis.
细胞外电子传递 (EET) 是微生物电解系统 (MES) 中细菌和电极之间电子传递的重要途径。为了增强 MES 中的 EET，将高导电性聚合物聚吡咯 (PPy) 原位涂覆在混合培养产乙酸菌的表面，并将涂有 PPy 的细菌接种到 MES 的阴极上。PPy 涂层生物阴极的电荷转移电阻比未涂覆 PPy 的降低了 30%到 70%。在 PPy 涂层生物阴极中，乙酸盐的产率和法拉第效率提高了 3 到 6 倍。经过 960 小时的运行，在涂覆和未涂覆的生物阴极上，优势菌属分别为醋杆菌属、脱硫弧菌属和不动杆菌属。醌环和 NADH 脱氢酶到泛醌参与了生物阴极的电子传递途径，并受到 PPy 涂层的刺激。生物阴极上 C 型细胞色素的低水平表达表明其在向内 EET 中的作用不那么重要。该研究为高导电性化学物质在微生物电解合成中的应用提供了有用的信息。
