硝尔库勒湖沉积物中非培养放线菌多样性

目的]认识和了解盐湖沉积环境中放线菌的多样性,为今后的开发和利用奠定基础.方法]应用免培养技术和基于16S rRNA基因序列的系统发育分析对新疆硝尔库勒盐湖沉积物中放线菌的多样性进行了研究.实验采用SDS-CTAB法提取土样中总DNA,利用放线菌特异性引物对土样总DNA进行16S rRNA基因扩增,并构建16S IRNA基因克隆文库;对随机挑选的160个克隆通过酶切筛选出51个不同图谱的重组克隆,并对其测序.结果]所获得的51个克隆序列属于39个OTUs,其中52.9%的克隆序列分布于放线菌门(phylum Actinobacteria)放线菌亚(Actinobacteridae)的5个亚目和酸微菌亚纲(Acidimicrobidae)中,并且在这两个亚纲中有大量克隆序列属于放线菌的新类群,另外47.1%的克隆序列以极高的自展值在放线菌门内支持形成一个独立的大分支,极有可能代表一个新亚目或更高级分类单元的类群.结论]这些研究结果说明硝尔库勒盐湖中存在有较为丰富的放线菌系统发育多样性,并且潜藏着新类型的放线菌资源.

Actinobacterial diversity of a sediment sample from Xiaoerkule Lake

Objective] The aim of study was to investigate Actinobacterial diversity in Xiaoerkule salt lake, to lay a foundation for furthering to tap. Methods] Actinobacterial diversity in this sediment from Xiaoerkule Lake was investigated by culture-independent method and phylogenetic analysis based on 16S rRNA gene sequences. Total DNA of sediment sample was extracted using SDS-CTAB method. The primers for the class Actinobacteria were used for actinobacterial 16S rRNA gene amplification and then a clone library was constructed for the sediment sample. Results] Fifty-one clones screened from 160 clones on the basis of Hae III digestion patterns were sequenced, and their sequences were deposited in the GenBank. Clone sequences (52.9%) belonged to Acidimicrobidae and 5 suborders of Actinobacteridae. The other clone sequences (47.1%), which formed one large distinct clade in phylogenetic tree among phylum Actinobacteria, may represent one new suborder or new class. Conclusion] There was abundant actinobacterial diversity in the sediment of Xiaoerkule Lake, and the result implied that there were large numbers of unknown actionobacterial groups here.