中国江苏太湖和阳澄湖细菌群落组成、多样性和时空动态比较研究

Comparison of the Composition,Diversity and Spatiotemporal Dynamics of Bacterial Communities in Lake Taihu and Lake Yangcheng,Jiangsu,China

为了调查与比较太湖和阳澄湖浮游细菌群落的分布、多样性及动态,采用密集时间(每周)采样法于2012年6月至10月采集了85个样品,并通过16S rRNA基因高通量测序分析了其菌群组成。原始读长序列经过滤后,共获得142354条高质量读长序列,归属于4589个运算分类单元(operational taxonomic units,OTUs),其中变形菌门(主要包括γ-变形菌门)和拟杆菌门是两个湖泊的主要类群。两个湖泊的菌群共同拥有19.55%的OTUs,这些OTUs占总读长序列条数的95.01%,表明它们之间存在高度重叠。阳澄湖的群落α-多样性高于太湖,这可能主要归因于两个湖泊的稀有菌群。有趣的是,我们观察到浮游细菌群落的组成随时间急剧波动,推测在极浅湖泊中菌群抵抗外来干扰的能力较低。综上所述,本研究结果对人们更好地理解湖泊菌群的组成差异及时空动态具有重要参考价值。

To investigate and compare the distribution,diversity and dynamics of bacterioplankton communi ties in Lake Taihu and Lake Yangcheng in Jiangsu Province,China,the bacterial community composition was analyzed from 85 samples using 454-pyrosequencing of 16S rRNA genes.The samples were taken weekly within an intensive time period from June to October 2012.A total of 142354 clean reads were generated that were assigned to 4589 operational taxonomic units(OTUs),with Proteobacteria(mainly γ-Pro teobacteria)and Bacteroidetes being the dominant taxa in both lakes.In addition,19.55%of OTUs,accounting for 95.01%of the total reads,were shared by bacterial communities in the two lakes,which indicated a high degree of overlap between them.The communities in Lake Yangcheng had a higher α-diversity than those in Lake Taihu,which may be mainly attributed to the rare taxa found in both lakes.Interestingly,the results showed that the bacterioplankton composition profile dramatically fluctuated over time.This may be explained by the low capability of the communities to resist external disturbances in extremely shallow lakes.Our study provides information for better understanding of the spatiotemporal dynamics in bacterial commu nities and differences in their compositions between two related lakes.