【摘要】 浮游细菌是湖泊水体物质循环和能量流动过程中的关键要素,影响着整个生态系统的迁移转化。为探索中国北方典型内陆封闭型湖泊浮游细菌群落结构对环境因子变动的响应,以夏季内蒙古达里诺尔湖(以下简称"达里湖")为例,采集表、底层水共32个样品,基于16SrRNA基因测序,详细分析了浮游细菌群落结构的表、底层变化特征及其主要影响因素,结果显示:(1)夏季达里湖水体中浮游细菌群落多样性和均匀度均呈现表层>底层,丰富度则呈底层>表层。(2)浮游细菌群落以变形菌门(Proteobacteria)、放线菌门(Actinobacteria)、蓝细菌门(Cyanobacteria)和拟杆菌门(Bacteroidetes)四大优势菌门为主要组成部分,且变形菌门含量在表、底层水体中均占绝对优势:在底层水中占比46.46%,在表层水中占比36.21%。(3)基于不同环境因子和浮游细菌优势菌门间的Pearson相关性分析,表层水体中总溶解性固体(TDS)、溶解态无机磷(DIP)是多数优势菌门的主要驱动因子,而底层水体中的总氮(TN)、叶绿素a(Chl a)和水温(WT)为主要驱动因子。总的来说,达里诺尔湖表、底层浮游细菌群落结构与不同环境因子间存在显著相关,而水体环境因子的表、底层差异是影响多数优势菌门演化的重要因素。更多还原

【Abstract】 Bacterioplankton is the key element in the material cycle and energy flow in lake, affecting the migration and transformation of the ecosystem. In this paper, we collect 32 water samples from the surface and bottom water in summer Dali-nor Lake, which locates in Inner Mongolia Plateau and is an inland closed lake. Based on the T-RFLP technology and 16 S rRNA sequencing, the community structure of bacterioplankton and its vertical variation characteristics were analyzed in detail. In summer, the diversity and evenness of the bacterioplankton in surface water are higher than bottom water.Meanwhile, bottom water has the highest species richness. On the whole, the Proteobacteria, Actinobacteria, Cyanobacteria,and Bacteroidetes are the dominant phyla in summer Dali-nor Lake. The Proteobacteria is the most dominant phylum in all water layers, with the content of about 46.46% in bottom water, and about 36.21% in surface water, respectively. Furthermore,TDS, DIP in surface water are correlated with most dominant bacteria, TN, Chl a and WT in the bottom water are the main environmental factors influencing community distribution. In summary, the re is a significant correlation between the surface and bottom planktonic bacterial community structure of Dali-norl Lake and different environmental factors, while the water environmental factors in surface and bottom waters have become important factors affecting the evolution of most dominant bacteria.更多还原