Metagenomic analysis reveals the response of microbial community and function in lake sediment to environmental factors

Jingpo Lake is the largest mountain barrier lake in China, which plays a key role in breeding, power generation, and drinking water source. Microbes are important participants in the formation of lake resources and energy cycle. However, the ecological protection of Jingpo Lake is facing serious challenges in recent years. In this study, metagenomic sequence was used to characterize the microbial community compositions of sediments from five sampling sites. We found that the diversity and composition of microbiota sediments were altered spatially and correlated with the physicochemical factors of water samples. The JP5 group had lower Chao1, ACE, Shannon, and Simpson indexes than other groups. Bacteroidetes was the most dominant phylum followed by Proteobacteria and Firmicutes, while at the genus level, Flavobacterium was highest in the JP5. Furthermore, KEGG analysis revealed that the metabolism function was the most abundant functional classification in Jingpo Lake. Meanwhile, the abundant functional categories in JP5 were carbohydrate metabolism and amino acid metabolism. The levels of TP, Chl a and pH were positively correlated with the abundance of Flavobacterium and bacterial function such as carbohydrate metabolism and amino acid metabolism. In conclusion, our results revealed the physical and chemical characteristics, and microbial community characteristics of Jingpo Lake, which provided a new insight for studying the relationship between environmental factors and bacterial community distribution of freshwater ecosystem, and also provided a theoretical basis for environmental monitoring and protection of the lake.