摘 要 ：为了解新疆沙湾冷泉沉积物的细菌群落组成与类群多样性，利用免培养方法直接从沙湾冷泉沉积物中提取环境总DNA，构建细菌16S rRNA基因文库。对随机挑选的241个细菌阳性克隆子进行Hae III 酶切分型得到86个可操作分类单元 (OTUs)，系统发育分析将其归为11个门：放线菌门(Actinobacteria)，酸杆菌门(Acidobacteria)，拟杆菌门(Bacteroidetes)，绿菌门(Chlorobi)，蓝细菌门(Cyanobacteria)，厚壁菌门(Firmicutes)，芽单胞菌门(Gemmatimonadetes)，硝化螺旋菌门(Nitrospirae)，变形菌门(Proteobacteria)，浮霉菌门(Planctomycetes)，疣微菌门(Verrucomicrobia)。其中酸杆菌门和变型菌门为优势类群，分别占细菌克隆文库的48%和25%。超过1/3的OTUs序列与GenBank中已存序列具有较低相似性 (相似性小于95%)。此外20%左右的克隆子与固氮细菌和硝酸盐氧化细菌相关。研究结果表明，新疆沙湾冷泉沉积物中细菌种类丰富，代谢类型多样而且存在大量未知类群。
Abstract:The bacterial composition and diversity in Xinjiang Shawan cold spring sediment were investigated by direct extracting environmental total DNA and constructing clone libraries of the 16S rRNA gene amplified with bacteria-specific primers. 241 bacterial clones were screened, which could be grouped into 86 Operational Taxonomic Units (OTUs), based on restriction fragment length polymorphism (RFLP) analysis. These were divided into 11 phyla (Actinobacteria Acidobacteria, Bacteroidetes,Chlorobi, Cyanobacteria, Firmicutes, Gemmatimonadetes, Nitrospirae, Proteobacteria, Planctomycetes and Verrucomicrobia) by phylogenetic analysis. Of these, Acidobacteria and Proteobacteria were the most dominant, representing 48% and 25% of the total bacteria clone library, respectively. More than 1/3 of the total OTUs showed less than 95% of sequence identity with sequences deposited in GenBank database. In addition, nearly 20% of clones were related to nitrogen-fixing and nitrite-oxidizing bacteria. These results suggested that bacteria in the spring sediment were highly diverse in species richness and maybe existence of large number of unknown groups.