崇明东滩夏冬季表层沉积物细菌多样性研究

摘要

Based on the total DNA extracted from the surface sediments of Chongming eastern tidal flat in the Yangtze estuary in summer and winter, the V3 area of 16S rRNA gene of bacteria were amplified. PCR products were cloned and sequenced, and 16S rRNA gene libraries were constructed. Phylogenetic analysis indicated that the bacteria in the surface sediments of Chongming eastern tidal flat fell into twelve known Phyla: Proteobacteria (α-,β-,γ-,δ-,ε-), Bacteroidetes, Actinobacteria, Acidobacteria, Chloroflexi, Firmicutes, Spirochaetes, Verrucomicrobia, Planctomycetes, Chlorobi, Dictyoglomi and Nitrospirae. Also, there were many sequences belonging to unidentified bacteria. Proteobacteria was the dominant group in the middle tidal flat and the low tidal flat, while Bacteroidetes was the dominant group in the high tidal flat. DOTUR analysis indicated that there were the most abundant species and highest bacterial community diversity in the middle tidal flat, followed by the low tidal flat, and the high tidal flat had the lowest bacterial community diversity. The bacterial community diversity was higher in summer than in winter. In comparison, the seasonal variation of bacterial communities in the sediment of the high tidal flat was the largest, and the variation in the middle tidal flat was the smallest.%以长江口崇明东滩高、中、低潮滩夏、冬两季表层沉积物中基因组DNA为模板,PCR扩增样品中细菌16S rRNA基因V3区片段,通过克隆、测序,构建相应基因文库.系统发育分析结果表明,崇明东滩高、中、低潮滩表层沉积物共包含12个主要门类的细菌:变形菌门(Proteobacteria)(α-、β-、γ-、δ-和ε-亚群)、拟杆菌门(Bacteroidetes)、放线菌门(Actinobacteria)、酸杆菌门(Acidobacteria)、绿弯菌门(Chloroflexi)、厚壁菌门(Firmicutes)、螺旋体门(Spirochaetes)、疣微菌门(Verrucomicrobia)、浮霉菌门(Planctomycetes)、绿菌门(Chlorobi)、网团菌门(Dictyoglomi)、硝化螺旋菌门(Nitrospirae),此外还存在大量未被认知的序列.中潮滩和低潮滩的优势菌为变形菌,高潮滩的优势菌为拟杆菌.DOTUR多样性分析结果表明,崇明中潮滩细菌多样性最高,低潮滩次之,高潮滩最低；夏季细菌多样性高于冬季.夏、冬两季细菌群落差异高潮滩最大,低潮滩次之,中潮滩最小.