乌梁素海小口湖区沉积物细菌多样性及其系统发育分析

DIVERSITY AND PHYLOGENETIC ANALYSIS OF BACTERIA IN SEDIMENTS OF XIAOKOU SITES IN LAKE WULIANGSUHAI

本文通过构建和分析细菌的16SrRNA基因克隆文库,研究了2008年7月乌梁素海小口湖区沉积物中微生物群落多样性及其系统发育。其中发现小口的49个克隆子主要与δ-proteobacteria(24.5%)Acidobacteria(18.4%),α-proteobacteria(14.3%),γ-proteobacteria(14.3%)和Chloroflexi(14.3%)相关。此外并通过多样性分析发现,富营养化较轻的小口湖区沉积物中细菌数量较多,多样性较完整,分布均匀。与其它相关研究比较发现,乌梁素海小口湖区发现的α-proteobacteria,Bacteroidetes均为淡水湖生态系统(例如太湖)中常见菌群,而Firmicutes,γ-pro-teobacteria等菌群多出现在太湖沉积物中,水体中很少。但是与典型淡水生态系统细菌群落组成不同的是乌梁素海中存在一部分的轻度嗜盐碱细菌。α,γ-proteobacteria,Bacteroidetes和Firmicutes,以及Chloroflexi的某些类群数量优势可能是对乌梁素海水体富营养化的响应。总之,细菌群落与水体富营养化关系紧密,但错综复杂、需要我们进一步深入研究。

This study investigated and analyzed the planktonic bacterial diversity and phylogeny of Lake Wuliangsuhai in 2008,by using the construction of 16S rRNA genes clone library.Totally 49 clones were affiliated to δ-proteobacteria（24.5%）,Acidobacteria（18.4%）,α-proteobacteria（14.3%）,γ-proteobacteria（14.3%）and Chloroflexi（14.3%）.In addition and through diversity analysis found that eutrophication lighter Xiaokou sites sediment of bacteria quantity,diversity,distribution uniformity intact.Compared with related study found that α-proteobacteria,Bacteroidetes in xiaokou sites of Wuliangsuhai were widely found in freshwater ecosystem（such as tai lake）,whereas γ-Proteobacteria and Firmicutes were more common in appear in sediments,and were rarely in water.But different from typical freshwater ecosystems bacterial community composition,the exist part of slightly halo-and-alkaline-philic bacteria in Lake Wuliangsuhai.In Lake Wuliangsuhai,that α,γ-proteobacteria,Bacteroidetes,Firmicutes and Chloroflexi dominant the bacteria maybe be responded to the eutrophication.Concludedly,bacteria community closely relates with water eutrophication though it is so complicated and needs further researches.