微生物燃料电池降解苯酚过程中微电场对阴极微生物多样性的影响

背景]苯酚废水作为一种毒性强、难降解的废水而备受关注。目前,微生物燃料电池(microbial fuel cell,MFC)已经广泛用于苯酚废水的降解,MFC的产电效果和苯酚的降解效率与反应器内的微生物群落有着密切关系。目的]为了提高MFC的产电效果及对有害物质的降解能力,需要对MFC中苯酚的降解和微生物群落结构进行探索。方法]分别在开路和闭路情况下,利用高效液相色谱(HPLC)测试MFC对苯酚的去除率;利用16S rRNA基因高通量测序技术分析阴极室中微生物群落的变化。结果]与开路控制相比,闭路情况下苯酚的去除效率有了显著提升。并且阴极微生物的物种多样性增多,尽管整体的物种丰度减少了,但一些产电菌和降解菌的丰度明显增加,例如门水平上的变形菌门(Proteobacteria)、放线菌门(Actinobacteria)和纲水平上的γ-变形菌纲(Gammaproteobacteria)。结论]微电场的存在促进了一些功能微生物的生长,对苯酚的降解和MFC的产电产生了积极影响。

Effect of micro electric field on cathode microbial diversity in the process of phenol degradation in microbial fuel cell

Background] Phenol wastewater has attracted much attention as a kind of wastewater with strong toxicity and refractory degradation. At present, microbial fuel cell (MFC) have been widely used for the degradation of phenol wastewater. The power generation efficiency of MFC and the degradation efficiency of phenol are closely related to the microbial community in the reactor. Objective] In order to improve the electricity generation effect of MFC and the degradability of harmful substances, it is necessary to explore the degradation of phenol in MFC and the structure of microbial community. Methods] In open and closed circuit condition, high-performance liquid chromatography (HPLC) was used to test the removal rate of phenol by MFC; 16S rRNA gene high-throughput sequencing technology was used to analyze changes in the microbial community in the cathode compartment. Results] The results showed that compared with open circuit control, the removal effect of phenol in closed circuit condition has been significantly improved. In addition, the species diversity of cathodic microorganisms has increased. Although the overall species abundance has decreased, the abundance of some electricity-producing and degrading bacteria has increased significantly, such as, Proteobacteria and Actinobacteria at the phylum level and Gammaproteobacteria at the class level. Conclusion] The existence of the micro electric field promotes the growth of some functional microorganisms, which has a positive impact on the degradation of phenol and the power generation of MFC.