Xia Zhanfeng, Guan Tongwei, Ruan Jisheng, Huang Ying, Zhang Lili
Key Laboratory of Protection and Utilization of Biological Resources in Tarim Basin of Xinjiang Production & Construction Corps; Tarim University, Alar 843300, China.
Wei Sheng Wu Xue Bao. 2011 Aug;51(8):1023-31.
This study aims at investigating the diversity of actinobacteria in Aiding Lake, a hypersaline lake and the lowest land point in China.
The diversity of actinobacteria in the sediment from Aiding Lake was investigated by culture--independent method based on phylogenetic analysis of 16S rRNA gene sequences and selective isolation. 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. Nine selective media with different salinities were used to isolate actinobacteria from the sediment samples.
The analysis of 16S rRNA gene sequences showed that 273 clone sequences belonged to subclasses Actinobacteridae (208), Acidimicrobidae (13) and Rubrobacteridae (52). The dominant actinobacteria was genus Rothia, which accounted for 37% of total clones. The similarity between 45.8% of 273 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. Fifty-five strains were isolated by different selective media. They belonged to six suborders of the order Actinomycetales, of which Streptomyces and Nocardiopsis were the dominant groups. Six potential new species were obtained.
Aiding Lake harbors abundant actinobacteria, including large number of unknown actinobacterial groups.
本研究旨在调查艾丁湖（中国的一个高盐湖和最低点）中放线菌的多样性。
采用基于16S rRNA基因序列系统发育分析和选择性分离的免培养方法，对艾丁湖沉积物中的放线菌多样性进行研究。使用特异性引物扩增放线菌16S rRNA基因，并为沉积物样本构建相应的克隆文库。根据Hae III酶切模式选择不同的克隆进行测序。使用9种不同盐度的选择性培养基从沉积物样本中分离放线菌。
16S rRNA基因序列分析表明，273个克隆序列属于放线菌亚纲（208个）、酸微菌亚纲（13个）和红杆菌亚纲（52个）。优势放线菌为罗氏菌属，占总克隆数的37%。273个检测序列中45.8%与已发表序列的相似性小于97%，可能代表新的分类单元。一些在系统发育树中形成几个不同分支的序列可能代表放线菌的新分类群。通过不同的选择性培养基分离出55株菌株。它们属于放线菌目的6个亚目，其中链霉菌属和诺卡氏菌属为优势菌群。获得了6个潜在的新物种。
艾丁湖蕴藏着丰富的放线菌，包括大量未知的放线菌群。
