新疆塔里木盆地可培养嗜盐放线菌系统发育多样性

Phylogenetic Diversity of Halophilic Actinomycetes from Hypersaline Environments in Tarim Basin of Xinjiang, China

摘要:

应用纯培养手段和基于16S rRNA基因序列的系统发育分析, 对从塔里木盆地高盐环境土壤样品中分离的18株可培养嗜盐放线菌多样性进行了研究。实验结果表明, 18株嗜盐放线菌可归为3个科(Glycomycetaceae、Pseudonocardineae和Nocardiopsaceae), 在有效发表的5个属的嗜盐放线菌中有4个属的嗜盐放线菌被分离到。多数菌株属于Actinopolyspora属(38.9%)、Nocardiopsis属(27.8%)和Streptomonospora属(22.2%), 是塔里木盆地高盐环境中嗜盐放线菌的优势类群。这些分离菌株中, 菌株YIM 92370与最近种的相似性为92%, 在Glycomycetaceae科内形成一个独立的分支, 极有可能代表Glycomycetaceae科的一个新属。研究结果表明塔里木盆地高盐环境中存在有较为丰富的嗜盐放线菌系统发育多样性, 并且潜藏着新类型的放线菌资源。

Abstract:

Phylogenetic diversity of halophilic actinomycetes from hypersaline environments in Tarim basin was investigated by using culture-dependent method and phylogenetic analysis based on 16S rRNA gene sequences. The results showed that the eighteen isolates, which were isolated from different hypersaline soil samples isolates belongs to three different families(Glycomycetaceae, Pseudonocardineae and Nocardiopsaceae) of the order Actinomycetales, and the most abundant and diverse isolates were within the Actinopolyspora(38.9%), Nocardiopsis(27.8%) and Streptomonospora(22.2%). In addition, four of the five known genera isolates were obtained for those halophilic Actinomycetes. Interestingly, strain YIM 92370 formed one distinct clade in phylogenetic tree based on 16S rRNA gene sequences among the family Glycomycetaceae, and it was noted that strain YIM 92370 is phylogenetically nearest to the genera Glycomyces and Stackebrandtia, but apparently is not a member of the two known genera or any of the other currently described actinomycetal genera. So it is proposed that the strain represents a new genus within the family Glycomycetaceae with 92% sequence similarity with the described species of this family. The results indicated that there was not only abundant phylogenetic diversity of halophilic actinomycetes, but also some unknown actionobacterial groups existed in hypersaline environments in Tarim basin.