Guo Yating, Wang Guozhen, Zhang Hao, Wen Hongyu, Li Wen
School of Life Sciences, Jiangsu Normal University, 101 Shanghai Road, Xuzhou, 221116 Jiangsu China.
Biotechnol Biofuels. 2020 Sep 21;13:162. doi: 10.1186/s13068-020-01800-1. eCollection 2020.
Extracellular electron transfer (EET) is essential in improving the power generation performance of electrochemically active bacteria (EAB) in microbial fuel cells (MFCs). Currently, the EET mechanisms of dissimilatory metal-reducing (DMR) model bacteria and have been thoroughly studied. has also been proved to be an EAB capable of EET, but the EET mechanism has not been perfected. This study investigated the effects of biofilm transfer and electron mediators transfer on sp. 203 electricity generation performance in MFCs.
Herein, we covered the anode of MFC with a layer of microfiltration membrane to block the effect of the biofilm mechanism, and then explore the EET of the electron mediator mechanism of sp. 203 and electricity generation performance. In the absence of short-range electron transfer, we found that sp. 203 can still produce a certain power generation performance, and coated-MFC reached 40.26 mW/m at a current density of 770.9 mA/m whereas the uncoated-MFC reached 90.69 mW/m at a current density of 1224.49 mA/m. The difference in the electricity generation performance between coated-MFC and uncoated-MFC was probably due to the microfiltration membrane covered in anode, which inhibited the growth of EAB on the anode. Therefore, we speculated that sp. 203 can also perform EET through the biofilm mechanism. The protein content, the integrity of biofilm and the biofilm activity all proved that the difference in the electricity generation performance between coated-MFC and uncoated-MFC was due to the extremely little biomass of the anode biofilm. To further verify the effect of electron mediators on electricity generation performance of MFCs, 10 µM 2,6-DTBBQ, 2,6-DTBHQ and DHNA were added to coated-MFC and uncoated-MFC. Combining the time-voltage curve and CV curve, we found that 2,6-DTBBQ and 2,6-DTBHQ had high electrocatalytic activity toward the redox reaction of sp. 203-inoculated MFCs. It was also speculated that sp. 203 produced 2,6-DTBHQ and 2,6-DTBBQ.
To the best of our knowledge, the three modes of EET did not exist separately. sp.203 will adopt the corresponding electron transfer mode or multiple ways to realize EET according to the living environment to improve electricity generation performance.
细胞外电子转移（EET）对于提高微生物燃料电池（MFC）中电化学活性细菌（EAB）的发电性能至关重要。目前，异化金属还原（DMR）模式细菌的EET机制已得到深入研究。[细菌名称]也被证明是一种能够进行EET的EAB，但其EET机制尚未完善。本研究调查了生物膜转移和电子介体转移对[细菌名称]sp. 203在MFC中发电性能的影响。
在此，我们用一层微滤膜覆盖MFC的阳极，以阻断生物膜机制的影响，然后探究[细菌名称]sp. 203的电子介体机制的EET和发电性能。在没有短程电子转移的情况下，我们发现[细菌名称]sp. 203仍能产生一定的发电性能，涂覆微滤膜的MFC在电流密度为770.9 mA/m²时达到40.26 mW/m²，而未涂覆的MFC在电流密度为1224.49 mA/m²时达到90.69 mW/m²。涂覆微滤膜的MFC和未涂覆的MFC之间发电性能的差异可能是由于阳极覆盖的微滤膜抑制了阳极上EAB的生长。因此，我们推测[细菌名称]sp. 203也可以通过生物膜机制进行EET。蛋白质含量、生物膜完整性和生物膜活性均证明，涂覆微滤膜的MFC和未涂覆的MFC之间发电性能的差异是由于阳极生物膜的生物量极少。为了进一步验证电子介体对MFC发电性能的影响，将10 μM 2,6 - 二叔丁基对苯二醌（2,6 - DTBBQ）、2,6 - 二叔丁基对苯二酚（2,6 - DTBHQ）和二氢萘醌（DHNA）添加到涂覆微滤膜的MFC和未涂覆的MFC中。结合时间 - 电压曲线和循环伏安曲线，我们发现2,6 - DTBBQ和2,6 - DTBHQ对接种[细菌名称]sp. 203的MFC的氧化还原反应具有高电催化活性。还推测[细菌名称]sp. 203产生了2,6 - DTBHQ和2, – DTBBQ。
据我们所知，三种EET模式并非单独存在。[细菌名称]sp.203会根据生存环境采用相应的电子转移模式或多种方式来实现EET，以提高发电性能。
Zotero 插件
