微生物燃料电池阳极生物膜微生物群落的PCR-DGGE分析

以养殖废水沼气池沼泥为接种物,构建了乙二胺、三氯化铁改性阳极的无介体单室微生物燃料电池（MFC）体系,均成功实现了连续产电,同时对废水中的污染物也具有很好的去除效果。为了更好地研究微生物燃料电池阳极生物膜的微生物多样性,分别采集了两种MFC阳极生物膜样品,采用PCR-DGGE法研究了一个完整产电周期的启动期（S）、葡萄糖产电稳定期（RG）和养殖废水原水稳定期（RS）的MFC阳极生物膜的微生物群落变化。结果表明,不同时期MFC阳极生物膜的微生物多样性存在明显差异,S-RG、S-RS、RG-RS的微生物群落相似性分别为70.1%、42.0%和50.6%。两种不同阳极富集的生物膜微生物群落相似性仅为48%,这表明不同改性方法所得的阳极对微生物具有选择性作用。对DGGE条带测序和比对发现,不同时期阳极生物膜上优势微生物包括Trichococcus sp.、Thauera sp.、Azoarcus sp.、Azospirillum sp.、Zobellella sp.、Pseudomonas sp.、Aeromonas sp.、Thiobacillus sp.、Desulfovibrio sp.、Thiomonas sp.,其中Pseudomonas sp.、Aeromonas sp.和Desulfovibrio sp.与已报道的相关产电微生物具有较高的序列相似度,这些菌种可能是本MFC体系中的主要产电菌。

Microbial Community of Anodic Biofilm of Microbial Fuel Cells Revealed by PCR-DGGE Analysis

Two microbial fuel cells （MFCs） equipped with ethylenediamine and ferric trichloride modified anodes were operated continuously by using swine manure marsh-gas tank sludge as the inoculums. The MFCs could generate electricity from wastewater, and the pollutants could also be efficiently removed as well. In order to better understand microbial community of the anodic biofilm of the MFCs, the anodic biofilm samples of the MFCs including start-up phase （S）, electricity-producing stationary phase （RG）, and real wastcwater electricity-pro- ducing stationary phase（ RS ） were collected and analyzed by using PCR-DGGE method. The results showed that the microbial diversity ap- peared significant differences among the different anodic biofilm samples. The microbial community similarity of S-RG, S-RS and RG-RS was 70.1%, 42.0 % and 50.6 %, respectively. Besides, the microbial community similarity of the anodic biofilm of the two MFCs when fed with raw wastewater was only 48.0 %, which implied that the anodes modified with the two different methods had a selective effect on mi- crobes. The sequencing and comparison of the DGGE bands revealed that the dominant bacteria of the anodic biofilm were Trichococcus sp., Thauera sp., Azoarcus sp., Azospirillurn sp., Zobellella sp., Pseudomonas sp., Aeromonos sp., Thiobaciilus sp., Desulfovibrio sp., and Thiomonas sp., respectively. Among them, Pseudomonas sp. ,Aeromonas sp. and Desulfovibrio sp. were the possible high electrochemically active bacteria in this study. It was indicated that the microbial community structures were significantly different among the different biofilm samples and the anodes modified by different methods. The results provide an academic basis for understanding the development of anodie biofilm of MFCs.