青藏高原察尔汗盐湖地区可培养中度嗜盐菌的群落结构与多样性

Community structure and diversity of culturable moderate halophilic bacteria isolated from Qrhan salt lake on Qinghai-Tibet Plateau

摘要:

[目的]研究青海察尔汗盐湖地区的可培养中度嗜盐菌的群落结构及多样性。[方法]采用多种选择性培养基进行中度嗜盐菌的分离、培养；通过16S rRNA基因序列扩增、测定，根据序列信息，进行系统进化树构建、群落结构组成分析及多样性指数计算。[结果]从察尔汗盐湖卤水及湖泥中分离到中度嗜盐菌421株，合并重复菌株后共83株中度嗜盐菌。菌株16S rRNA基因序列信息显示，4株中度嗜盐菌为潜在的新分类单元。83株嗜盐细菌分布于3个门的6个科16个属。其中，Bacillus属、Oceanobacillus属和Halomonas属为优势属。多样性结果显示，水样中的菌株多样性高于泥样，而泥样中的菌株优势度高于水样。[结论]察尔汗盐湖中度嗜盐菌具有丰富的遗传多样性，种群种类丰富，优势菌群集中，该盐湖地区存在可分离培养的中度嗜盐菌的疑似新物种。

Abstract:

[Objective] I studied the community structure and diversity of culturable moderate halophilic bacteria isolated from Qrhan Salt Lake.[Methods] I isolated and cultured the moderate halophilic bacteria on different selective media. After the 16S rRNA gene sequences was amplified and measured, I constructed the phylogenic tree, analyzed the community structure and calculated the diversity indexes according to the 16S rRNA gene information. [Results] A total of 421 moderate halophilic bacteria were isolated from water and mud samples in Qrhan Salt Lake. The 16S rRNA gene information showed that 4 potential novel species belonged to the family Bacillaceae. Eighty-three model strains belonged to 3 phylurms 6 families 16 genus. Among them, Bacillus sp., Oceanobacillus sp. and Halomonas sp. were dominant species. Diversity analysis showed that the diversity of strains isolated from water sample was higher than that from mud sample, but the dominance degree of strains isolated from mud sample was higher than that from water sample. [Conclusion] The genetic diversity of moderate halophilic bacteria isolated from Qrhan Salt Lake was abundant. Also, there were dominant and novel species of culturable moderate halophilic bacteria in this lake.