新疆玛纳斯热气泉免培养土壤细菌多样性分析

Bacterial diversity in a hot gas spring soil of MaNasi County, Xinjiang by culture-independent approach

摘要:

摘要：【目的】了解新疆玛纳斯热气泉土壤免培养细菌群落组成及多样性。【方法】采用免培养法直接从土壤样品中提取总DNA，利用细菌通用引物对土壤总DNA进行16S rDNA扩增，构建细菌16S rDNA文库。使用Hae III限制性内切酶对阳性克隆进行限制性片段长度多态性分析(restriction fragment length polymorphism, RFLP)，挑选具有不同酶切图谱的克隆进行测序、比对并构建16S rDNA 系统发育树。【结果】从土壤细菌16S rDNA文库中随机挑选了170 个阳性克隆，共得到29个不同的分类单元(operational taxonomic unit,OTU)。系统发育分析归为6个门：酸杆菌门(Acidobacteria)、放线菌门(Actinobacteria)、拟杆菌门(Bacteroidetes)、厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)和浮霉菌门(Planctomycetes)。其中厚壁菌门(Firmicutes)为绝对优势类群，占整个细菌文库的71%。29个OTUs中有14条序列与GenBank中相关序列的相似性低于97%(序列长度约1.5 kb)，占序列总数的48%。【结论】热气泉土壤细菌种群多样性较低，但存在大量潜在细菌新种。

Abstract:

Abstract：[Objective] In order to investigate bacteria diversity in a hot gas spring soil of MaNasi county, Xinjiang. [Methods] Total DNA were directly extracted from the soil of a hot gas spring from Xinjiang.16S rDNA were amplified directly from purified DNA by PCR with universally bacteria-specific rDNA primers and cloned. Positive clones were identified by restriction fragment length polymorphism(RFLP), and unique rDNA types clones were sequenced, analysed and then constructed phylogenetic tree. [Results] Twenty-nine operational taxonomic units (OTU) from 170 positive clones were found belonging to 6 phyla: Firmicutes, Proteobacteria, Acidobacteria, Bacteroidetes, Planctomycetes, Actinobacteria. Firmicutes (71%) was the absolutely dominant components of the soil bacterial community. 14 sequences (about 1.5 kb) from 29 OTUs showed less affiliation with known taxa(<97% sequence similarity).[Conclusion] Soil bacterial diversity is low in the hot gas spring soil, but exit a large number of new unknown taxon in this environment.