Bacterial community structure and diversity of sediments in a typical plateau lakeshore

Abstract:

[Background] Eutrophication of plateau lakes is becoming increasingly serious. Lakeshore zone is the protective barrier for the lake and has effects on intercepting and purifying the external pollutants. Changes of water environment affect the sediment bacteria. [Objective] The aim of the present work was to explore the relationship between lakeshore sediment bacterial community structural characteristics and water bodies eutrophication. [Methods] Bacterial community structure and the diversity of eight sediments in the south bank of Yangzonghai Lake was analyzed by 16S rRNA gene high-throughput sequencing technology. Principal component analysis and redundant analysis were analyzed by comparing the differences in environmental factors of different waters, and the effects of eutrophic water on bacterial community structure and abundance in sediments. [Results] Lakeshore sediments had a certain response to water eutrophication. In high eutrophication areas (S3), the bacterial richness was high with a high OTU at 1 473. Conversely, in areas with low levels of eutrophication (S1), the bacterial richness was low and the OTU was 730. The dominant bacteria in Yangzonghai Lake lakeshore were Proteobacteria and Chloroflexi with a small group of Actinobacteria, Actidobacteria and Firmicutes. Chloroflexi was closely related to eutrophication degree in water. In moderately eutrophic areas, the proportion of Chloroflexi was as high as 44.1%, while in the light eutrophication area Chloroflexi was only 15.6%. Basing on environmental factor analysis, it was found that the bacterial community of Yangzonghai Lakeshore sediment was strongly affected by total phosphorus, chlorophyll a and total nitrogen. [Conclusion] The results clarified the structure and variation characteristics of bacterial populations in plateau lakes lakeshore and their responses to water eutrophication, helps to better the understanding of sediment bacteria in plateau lakes and provide a theoretical basis for prevention and control eutrophication in plateau lakes.