新疆两盐湖可培养嗜盐古菌多样性研究

Biodiversity of halophilic archaea isolated from two salt lakes in Xin-Jiang region of China

从新疆地区艾比盐湖和艾丁盐湖卤水及泥土样品中分离到86株嗜盐古菌。16S rRNA基因序列分析结果表明,分离自艾比湖的嗜盐古菌分别属于Haloarcula、Halobacterium、Halorubrum、Haloterrigena、Natrinema和Natronorubrum6个属的11个分类单元,而分离自艾丁湖的嗜盐古菌分别属于Haloarcula、Halobiforma、Halorubrum、Haloterrigena、Natrialba、Natrinema6个属的8个分类单元,这一结果表明艾比湖可培养嗜盐古菌生物多样性稍高于艾丁湖。基于16S rRNA基因序列的系统发育分析表明代表菌株ABH15应为Natronorubrum属的中性嗜盐古菌新种,代表菌株ABH07、ABH12、ABH17、ABH19、ABH51和AD30可能是Halobacterium、Halorubrum、Haloterrigena、Haloarcula的新成员。

There are more than 1000 salt lakes situated in northern and western regions of China and 790 of these salt lakes are in Xinjiang Uigur Autonomous Region and Qinghai, Tibet, Inner Mongolia. To better understand halophilic archaeal diversity of salt lakes in Xinjiang, water and sediment samples were collected from two salt lakes, namely Aibi salt lake and Aiding salt lake, and the halophilic archaeal diversity of these samples was determined. Totally eighty-six halophilic archeal strains, of which 56 isolated from Aibi salt lake and 30 isolated from Aiding salt lake, were isolated respectively using CM agar medium. All the strains were subjected to 16S rRNA gene sequencing analysis. Similarity analysis based on 16S rRNA gene sequences of all these strains indicated that the isolates from Aibi salt lake belong to 11 different species of genera Haloarcula, Halobacterium, Halorubrum, Haloterrigena, Natrinema and Natronorubrum, and that the isolates from Aiding salt lake belong to 8 different species of genera Haloarcula, Halobiforma, Halorubrum, Haloterrigena, Natrinema. Among the 86 strains, members of Natronorubrum Natrinema, Halorubrum and Haloterrigena, are dominant groups in Aibi salt lake. However, the dominant group in Aibi salt lake are the members of Natrinema, Halorubrum and Haloterrigena. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strains ABHI3, ABH 14, ABH 15, ABH 18, ABH 31 and ABH 33 may represent a novel species of Natronorubrum; ABH12, ABH32 and AD30 two novel species of Halorubrum; ABH17 and ABH25, ABH51, ABH52, ABH56 two novel species of Haloterrigena respectively; strain ABH19 a novel species of Haloarcula; strain ABH0？ a novel species of Halobacterium. The Shannon-Wiener＇s index of Aibi salt lake is 1.899, the same index of Aiding salt lake is 1.317, which indicated that the biodiversity of halophilic archaea from Aibi salt lake was slightly higher than that of Aiding salt lake. Different characteristics in pH of salt concentrations, average annual precipitation, annual evaporation and mankind＇s impact on two salt lakes might play important roles on halophilic archaeal diversity of two salt lakes.