有机污染物对水体真细菌群落结构的影响

为了揭示有机污染物对环境真细菌组成和多样性的影响,应用末端限制性片段长度多态性(tRFLP)和16S rDNA文库技术并结合水质分析方法,比较分析了松花江流域内受不同程度有机污染的4个水体及其沉积物中真细菌的群落结构。tRFLP分析表明各水体及底泥均呈现较为复杂的群落结构模式,不同底泥群落形成的末端限制性片段(TRF)图谱具有很高的相似性,但随着污染程度的加强,部分类群明显富集,而且在水样组和泥样组内,群落结构的相似性同水质相似性是一致的,主成分分析(PCA)显示水样和泥样中的真细菌TRF形成不同的群。16SrDNA文库分析表明松花江哈尔滨段底泥中真细菌分布于10个门,Proteobacteria门占优势,达群落总数的21.92%(β-Proteobacteria亚门占10.96%),而有机染污物严重超标的生活污水排污道底泥中的微生物多样性较低,分布于7个门,Proteobacteria门为优势群,占群落的47.37%(α-Proteobacteria亚门占21.05%,δ/ε-Proteobacteria亚门占15.79%)。该研究表明向水体中长期排放高浓度有机物能使系统中微生物群落多样性降低,与污染物降解相关的功能微生物类群明显富集。

Influence of organic pollutants on the bacterial community in Songhua River drainage area

In order to investigate the potential influence of the organic pollutants on the microbial composition and diversity, terminal restriction fragment length polymorphism (tRFLP) and 16S ribosomal DNA (rDNA) clone libraries combined with water quality analysis were selected to compare the structure of bacterial communities in four water bodies contaminated by different degrees of organic matter. tRFLP profiles of the waters and sediments all showed complex patterns and high similarity, however, some certain populations enriched with the pollution enhanced. Especially, the similarity of communities accorded strictly with that of water quality. Principal component analysis (PCA) indicated that the terminal restriction fragments (TRF) of bacteria in the waters and sediments grouped into different clusters. 16S ribosomal DNA sequences in the Songhua River sediment fell into ten known phyla and Proteobacteria are predominant with 21.92% of clones (in which the beta-Proteobacteria accounts for 10.96%). The sediment seriously polluted by domestic wastewater comprised of only 7 phyla, in which Proteobacteria was predominant with 47.37% of clones (subdivisions a-Proteobacteria and delta/epsilon-Proteobacteria were 21.05% and 15.79%, respectively). This study demonstrated that the long-term drainage of organic wastewater reduced the microbial diversity, and some functional microbes that are responsible for the degradation of organic matter, became dominant.