拜城盐山免培养放线菌多样性研究

目的]研究新疆拜城盐山高盐环境中的放线菌多样性,为今后的开发和利用奠定基础.方法]应用基于16SrRNA基因序列的免培养技术和系统发育分析方法对拜城盐山样品中的放线菌多样性进行研究.采用SDS- CTAB方法提取样品中的总DNA,利用特异性引物扩增样品DNA中的放线菌16S rRNA基因,并构建放线菌16S rRNA基因克隆文库；通过比较酶切图谱,挑选克隆文库中的代表克隆,进行序列测定和BLAST比对分析.结果]构建的放线菌克隆文库共包含216个放线菌克隆.克隆序列经过BLAST比对分析,放线菌亚纲中的克隆有171个,占总克隆数的79.2;.酸微菌亚纲45个克隆,占总克隆数的20.8;,与GenBank中已知的微球菌16S rRNA基因序列最大相似度小于92;,是酸微菌亚纲中新的类群.优势放线菌为放线菌亚纲棒杆菌亚目诺卡氏菌科( Nocardiaceae)的红球菌属(Rhodococcus),占克隆总数的51.9;.有24.5;的序列与已有效发表菌株的序列相似性小于97;,部分序列形成了几个独立的进化分支,可能代表着放线菌新的类群.结论]拜城盐山存在着较为丰富的放线菌种类,并且潜藏着新类型的放线菌资源.

Actinobacterial Diversity of Yanshan in Baicheng Revealed by Culture-independent Method

Objective]This study aims at investigating the diversity of actinobacteria in Yanshan,a hypersaline hill in Baicheng of Xinjiang.Method]The diversity of actinobacteria in the hypersaline sample was investigated by culture - independent method based on phylogenetic analysis of 16S rRNA gene sequences and selective isolation method.Specific primers were used to amplify the actinobacterial 16S rRNA gene,and corresponding clone libraries were constructed for the sediment samples.Different clones selected on the basis of Hae III digestion patterns were sequenced.Result]The analysis of 16S rRNA gene sequences showed that 216 clone sequences belonged to subclasses Actinobacteridae(171) and Acidimicrobidae(45).The dominant actinobacteria was genus Rhodococcus,which accounted for 51.8%of total clones.The similarity between 24.5%of 216 detected sequences and published sequences were less than 97%,which might represent new taxa.Some sequences,which formed several distinct clades in phylogenetic tree,may represent new taxonomical groups of actinobacteria.Conclusion]Yanshan environment harbors abundant actinobacteria,including large number of unknown actinobacterial groups.