崇测冰帽不同的冰川样品可培养细菌群落结构差异

Difference of community structure among culturable bacteria in different glacial samples on Chongce Ice Cap

摘要:

[目的] 研究细菌群落组成在西昆仑崇测冰帽冰川雪样、冰碛物和土样中的差异。[方法] 通过传统的纯培养和菌株16S rRNA基因序列鉴定,分析菌株在门水平和属水平的群落结构。[结果] 冰川细菌由Actinobacteria、Firmicutes、Proteobacteria和Bacteroidetes 4个门组成。雪样以Proteobacteria为优势,而土样和冰碛物则以Actinobacteria为优势。在属的水平上,冰川土样中的优势属仅有Arthrobacter,雪样中的优势属主要有Methylobacterium、Modestobacter、Hymenobacter、Brevundimonas、Bacillus这5种。雪环境的细菌群落结构与冰碛物和土样的差异性较大,而冰碛物和土样之间的差异性不大。Skermanella可能为崇测冰帽所特有的细菌。[结论] 初步说明了在冰川退缩的气候环境下,冰川雪样细菌多样性的脆弱性, 以及冰川雪环境细菌资源保护的重要性。

关键词:可培养细菌;群落结构;崇测冰帽;冰川

Abstract:

[Objective] We studied the difference of bacterial community composition among glacial snow, moraine deposits and glacial soil on Chongce Ice Cap of West Kunlun Mountains. [Methods] Based on traditional culture-dependent and 16S rRNA sequence analysis, we analyzed the community structure of bacteria on the level of genus and phylum. [Results] Results show that glacial bacteria were composed of Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes on the phylum level. Glacial snow was dominated by Proteobacteria, whereas glacial soil and moraine deposits were dominated by Actinobacteria. On the genus level, glacial soil was dominated by Arthrobacter, while glacial snow was dominated by Methylobacterium, Modestobacter, Hymenobacter, Brevundimonas and Bacillus. Bacterial composition was similar between glacial soil and moraine deposits, but different from glacial snow. Skermanella may be unique on Chongce Ice Cap. [Conclusion] Our study indicated the vulnerability of bacterial diversity in glacial snow with glacial retreat, and the importance of bacterial resources preservation on glacial snow environments.

Key words:culturable bacteria;community structure;Chongce Ice Cap;glacier