摘要

      本研究以石墨电极和锰矿电极为基质，研究了基质类型对上流式微生物燃料电池人工湿地（UCW-MFC）污染物去除、抗药性基因（ARG）归宿和细菌群落演化的影响。采用UCW-MFC（Mn）对锰矿石进行处理，取得了较好的COD去除率和较高的细菌群落多样性及发电性能。然而，在石墨结构的UCW-MFC（s）中，废水中磺胺嘧啶（SDZ）的浓度较低，ARGs的总量也较低，这可能与较高的石墨吸附和过滤能力有关。值得注意的是，两种反应器都能去除97.8%以上的环丙沙星。SDZ、COD浓度、ARG丰度与细菌a-多样性指数呈显著负相关。LEfse分析表明，由于两种反应器的底物不同，细菌群落存在显著差异，典型的电活性细菌Geobacter在UCW-MFC（Mn）的阳极上得到了大量富集。相反，产甲烷菌（methanoseta）的相对丰度被抑制。PICRUSt分析结果进一步表明，UCW-MFC（Mn）阳极胞外电子转移相关功能基因的丰度增加，但产甲烷功能基因和多重耐药基因减少。冗余分析表明，底物类型、抗生素积累和细菌群落是影响ARGs的主要因素。通过网络分析，揭示了潜在的ARG主机以及ARGs和intI1的共存。

        This study assessed the influence of substrate type on pollutants removal, antibiotic resistance gene (ARG) fate and bacterial community evolution in up-flow microbial fuel cell constructed wetlands (UCW-MFC) with graphite and Mn ore electrode substrates. Better COD removal and higher bacterial community diversity and electricity generation performance were achieved in Mn ore constructed UCW-MFC (Mn). However, the lower concentration of sulfadiazine (SDZ) and the total abundances of ARGs were obtained in the effluent in the graphite constructed UCW-MFC (s), which may be related to higher graphite adsorption and filter capacity. Notably, both reactors can remove more than 97.8% of ciprofloxacin. In addition, significant negative correlations were observed between SDZ, COD concentration, ARG abundances and bacterial a-diversity indices. The LEfse analysis revealed significantly different bacterial communities due to the substrate differences in the two reactors, and Geobacter, a typical model electro-active bacteria (EAB), was greatly enriched on the anode of UCW-MFC (Mn). In contrast, the relative abundance of methanogens (Methanosaeta) was inhibited. PICRUSt analysis results further demonstrated that the abundance of extracellular electron transfer related functional genes was increased, but the methanogen function genes and multiple antibiotic resistance genes in UCW-MFC (Mn) anode were reduced. Redundancy analyses indicated that substrate type, antibiotic accumulation and bacterial community were the main factors affecting ARGs. Moreover, the potential ARG hosts and the co-occurrence of ARGs and intI1 were revealed by network analysis.

      https://www.sciencedirect.com/science/article/abs/pii/S0043135419307626?via%3Dihub