Community composition and spatial variation of bacteria in the sediments of a eutrophic fresh water urban lake, East Lake, Wuhan, China.

ABSTRACT

Objective: Sediment bacteria are the important biological factors for remediating of eutrophic environments. To enrich our understanding of the bacteria communities in eutrophic urban lake sediments for better environment protection and pollution control in urban lake eco-systems, we resolved the composition of bacteria communities and their spatial variation in the sediments of a middle-size eutrophic urban lake, East Lake. Methods: We used 16S rRNA gene RFLP and sequencing methods to generate the phylogeny information of the bacteria community, used principal coordinates analysis (PCoA) and canonical correspondence analysis (CCA) methods to resolve the relationship between East Lake and other lakes, and the relationship between environmental factors and the bacteria communities. Results: Sediments inhabited 13 phyla and 2 unclassified clusters. PCoA further revealed that the bacteria communities in three sub-lakes of East Lake sediments were closely related to the communities in similar eutropic lake environments, and divergent from the hypereutrophic sub-lake Miao Lake, which was also found to inhabit a relative abundant amount of Thermogymnomonas-type archaea. CCA further revealed that the distribution of bacteria was closely correlated with the carbon, nitrogen and phosphate contents in the sediments. Conclusion: The environment factors regulated the bacteria community composition and distribution. The results of this study providereference to the research, protection and pollution control on urban lake eco-systems.