白洋淀表层沉积物细菌多样性及影响因素

Bacterial diversity in surface sediments of Baiyangdian lake and its influencing factors

为探究不同富营养化水体沉积物中细菌群落结构的差异及驱动因素,以白洋淀表层沉积物细菌为研究对象,通过高通量测序方法,分析了2种富营养水平下细菌群落结构组成、多样性以及与环境因子的相关性。结果表明,细菌群落多样性随富营养化水平升高而下降;重度和中度富营养化水平下的细菌群落结构有差异,重度富营养化水平下绿弯菌门丰度显著提高。总体而言,不同污染程度水体沉积物细菌群落结构在门水平上没有明显差异,沉积物中的优势菌门依次为变形菌门(31%~43%)、绿弯菌门(10%~21%)和拟杆菌门(9%~20%)。微生物群落与环境因子相关性热图表明,上覆水TP和NH_(4)^(+)-N、底泥TP和NO_(3)^(-)-N是白洋淀水体底泥细菌群落多样性的主要影响因素。白洋淀不同富营养化水体沉积物细菌多样性存在差异,磷含量是细菌群落结构的制约因素。

The purpose of this study was to explore the differences and driving factors of bacterial community structure in sediments of different eutrophic water bodies in Baiyangdian Lake.The composition and diversity of bacterial community structure under two eutrophication levels in surface sediment,as well as their correlation with environmental factors,were studied through high-throughput sequencing.The results showed that the diversity of bacterial communities decreased with the increase of the eutrophication level.The bacterial community structure was different under the severe and moderate eutrophication levels,and the abundance of Chloroflexi increased significantly under the severe eutrophication level.However,there was no significant difference in the bacterial community structure in Phylum level with different eutrophication in generally.The predominant phylum in the sediments were Proteobacteria(31%~43%),Chloroflexi(10%~21%)and Bacteroidetes(9%~20%),respectively.The heatmap of the correlation between microbial communities and environmental factors revealed that TP and NH_(4)^(+)-N in surface water,TP and NO_(3)^(-)-N in sediments were the main influencing factors of bacteria community diversity in the Baiyangdian Lake.It can be concluded that the diversity of bacteria in sediment was dissimilar in different eutrophic water,and the phosphorus content was identified as the limiting factor of bacterial community structure in Baiyangdian Lake.