重金属污染对鄱阳湖底泥微生物群落结构的影响

Effect of heavy metals in the sediment of Poyang Lake estuary on microbial communities structure base on Mi-seq sequencing

利用Illumina平台高通量测序技术,分析了鄱阳湖4大河流(信江XS,饶河RS,修河SS,赣江GS)河口底泥微生物群落结构和多样性对底泥重金属污染的响应情况.结果表明,在测试的6种重金属离子中,Cu、Zn全量和有效态表现为RS、XS显著高于SS、GS,Mn全量和有效态在GS中显著最高,Pb有效态在XS显著最高,Pb全量、Cd全量和有效态、Cr全量和有效态在4条河流中无显著差异;经检测,鄱阳湖4河口底泥微生物群落主要有5大类,它们分别是:变形菌门(Proteobacteria)(32.54%~50.35%),酸杆菌门(Acidobacteria)(6.13%~13.13%),拟杆菌(Bacteroidetes)(4.38%~14.92%),疣微菌门(Verrucomicrobia)(6.42%~10.70%)和绿湾菌门(Chloroflexi)(3.21%~11.73%).多样性指数结果表明:GS、SS微生物多样性指数(Chao1和Shannon)高于RS,与重金属含量成反相关.相关性分析表明:重金属Cu、Zn、Cd、Pb、Cr、Mn和138个主要OTU显著相关,其中Cu、Cd和微生物门、属显著相关的OTU数量最多.变形菌门中有9个属和Cu有效量,5个属和Cd有效量显著正相关,这些正相关的菌群是土壤重金属污染修复的重要微生物种质资源.

An alternative approach based on the high-throughout Mi-seq sequencing technology was used in this study toanalyze microbial communities of the sediments polluted by heavy metals from Poyang Lake estuaries including Xinjiangriver (XS), Raohe river (RS), Xiushui river (SS) and Ganjiang river (GS), which aimed to understand how microbialcommunity composition response to different heavy metals (Cu、Zn、Cd、Pb、Cr and Mn). Contents of total Cu (T_Cu)and Zn (T_Zn) in RS and XS were significantly higher than those in other rivers (SS and GS), and the content of total Mn(T_Mn) in GS was the highest, but the content of available Pb (A_Pb) was the highest in XS among the four riverestuaries. On the other hand, total Pb (T_Pb), total and available Cd (T_Cd and A_Cd), and total and available Cr (T_Crand A_Cr) among four rivers estuaries had no significant difference with each other. The microbial communities exploredby 16S rRNA gene sequencing were distributing mainly in five broad taxonomic groups, which were Proteobacteria(32.54%~50.35%), Acidobacteria (6.13%~13.13%), Bacteroidetes (4.38%~14.92%), Verrucomicrobia (6.42%~10.70%) andChloroflexi (3.21%~11.73%). The microbial diversity index (Chao 1and Shannon) of SS and GS were much higher thanthose of the RS, which resulted from much higher heavy metals in RS than the others. Correlation analysis showed thatboth kinds (total and available) of heavy metal ions (Cu、Zn、Cd、Pb、Cr and Mn) measured had significantly positive ornegative relation with 138 operational taxonomic units (OTUS) among all OTUS (18921~32161) detected, and Cu and Zn had the most related OTU numbers among all metals. For example, A_Cu were positively related with nine generain Proteobacteria, and A_Cd positively related with five genera in the same phylum. These microbes may be the importantspecies resource for restoration of damaged water or land area polluted by heavy metals.