电化学参数影响下微生物电解池阳极膜上电活性微生物群落的变化

Community evolution of exoelectrogens on anodic biofilm in microbial electrolysis cells:Influence of electrochemical parameters

近些年来,微生物电解池(Microbial electrolysis cell,MEC)在产氢方面的应用深受关注。但是,作为MEC的生物催化剂,电活性微生物的群落与功能尚未阐述清楚。因此,本实验通过电化学测量和16S rRNA测序等技术,检测了不同电化学参数下MEC产氢产电的情况,并分析了阳极生物膜上电活性微生物的种群结构。电化学结果显示,在其他参数一致的情况下,单独设置电解电压为1.0 V、电极距离为1.5cm、并联电源数为3个的情况下,其对应的MEC所形成的阳极膜产氢潜力最大,分别是5.35、5.56和5.68 mol/(mol-G)(G,葡萄糖)。微生物种群结构显示,不同电化学参数下阳极膜富集的电活性微生物多样性与种群结构不同,其中,MEC性能较好的实验组中所形成的阳极生物膜上土杆菌属(Geobacter)和梭菌属(Clostridium)的丰度相对较高,但对应的阳极微生物多样性并非最为丰富。综上所述,不同电化学参数对电活性微生物相对丰度的影响,更可能是导致MEC产氢能力不同的因素。

Microbial electrolysis cells(MECs)attracted much research attention for hydrogen production in past decades.However,exoelectrogens,as the biological catalysts in MECs,their community and function in MECs were not well understood.Therefore,specific batch experiments and a thorough microbial community analysis of anodic biofilms were conducted that MECs were performed under different electrochemical parameters.When the other parameters remain unchanged with the applied voltage of 1.0 V,electrode spacing of 1.5 cm,and three parallel energy source independently,the results showed that the highest hydrogen production of MECs were appeared,corresponding with the value of 5.35,5.56,and 5.68 mol/mol-G(G,glucose),respectively.The microbial community analysis revealed a different diversity and population structure among various anodic biofilms,as while,Geobacter and Clostridium were highly abundant in the anodic biofilms from MEC groups with better performance,but the corresponding microbial diversity is not the most abundant.In summary,the influence of different electrochemical parameters on the relative abundance of electroactive microorganisms is more likely to be the factor that affects the hydrogen production capacity of MEC.