东天山地区庙儿沟雪坑中微生物多样性、群落结构与环境关系研究

Study on microbial diversity and community in Miaoergou snow of East Tianshan Mountains and their relation to climatic and environmental changes

摘要:

通过荧光计数、恢复培养和变形梯度凝胶电泳(DGGE),分析了东天山地区庙儿沟不同深度积雪中的可培养细菌数量、多样性及其群落结构。结果表明,东天山地区冰雪微生物数量和多样性指数与气候环境替代指标钙离子、镁离子、氯离子等具有相关性。该地区雪坑中细菌隶属于4个不同系统发育群:proteobacteria(α-,β-,γ-),CFB,HGC和LGC,其中CFB类和proteobacteria类为主要类群。与青藏高原、南北极冰雪中微生物的比较分析发现Paracoccu和Aquasalina属是该地区的特殊微生物类群。直接培养和DGGE分析发现不同深度雪坑中微生物数量和群落结构都有明显的变化。结果表明,由于东天山地区的特殊地理位置,该地区冰雪微生物具有其特殊性。

Abstract:

The different depth snow samples were collected from the Miaoergou glacier in East Tianshan Mountains regions，China. Total bacteria counts were established by 4′，6- diamino-2-phenylindole (DAPI). Both culture-dependent and culture-independent methods，denaturing gradient gel electrophoresis (DGGE)，were used to examine the bacterial diversity and community structure. The microbial abundance and diversity index have a close relationship with mineral particle concentration. These mineral particles，such as Ca²⁺，Mg²⁺ and Cl^- etc，are good indicators of climate and environment. The 16S rDNA gene both of cultured bacteria and DGGE band sequenced belong to following groups：proteobacteria（α-，β-，γ-），Cytophaga-Flavobacterium-Bacteroides(CFB)，High GC and Low GC. Among these，Proteobacteria and CFB are dominant groups. Compare with bacteria revealed from ice and snow in Qinghai-Tibet Plateau，South Pole and North Pole which have been reported，Paracoccu sp. and Aquasalina sp. are especially exist in this study area as far as we know. The microbial abundance and community structure are all changed obviously in different depth snow samples. It indicates that the snow bacteria community is influenced by many factors. The results show that because the special geographical position of the East Tianshan Mountains，microorganism in ice and snow of this area has its particularity.