Differentiation of Nitrogen and Microbial Community in the Sediments from Lake Erhai, Yunnan-Kweichow Plateau, China

As a famous plateau lake and a place rich in biodiversity located at the Hengduan Mountains, there is little research on microbial diversity and community composition in Erhai. In this study, 770,425 16S rRNA sequences had obtained at different depth samples. The abundance-based coverage estimates (ACE), Chao1, and Shannon indices indicated the high abundance and diversity of Erhai sediment microorganisms. And they were obviously affected by human disturbance.Gammaproteobacteria,Deltaproteobacteria,Bacteroidia,Anaerolineae,Phycisphaerae, andMethanomicrobiawere dominant bacteria and existed in almost all samples. The content of total nitrogen (TN) in sediments had a significant positive correlation betweenSyntrophus,Deltaproteobacteria,Desulfatiglans,Oxyphotobacteria,Clostridiales,Burkholderiaceae,Geobacter,Crenothrixspecies richness.Desulfobacca,Syntrophus,Deltaproteobacteria,Desulfatiglans,Gammaproteobacteria,Oxyphotobacteria, andClostridialeswere positively correlated with the nitrates in sediments. And the species richness ofDesulfatiglanswas correlated with NO2-. The RDA analysis was shown that dbRDA1 was affected mainly by the depth of lake, while the content of TN, NO3-, NO2-, and NH(4)(+)had the largest effect on dbRDA2. The results indicated the great relations between the diversity and composition of microbial communities and different forms of sediment nitrogen in Erhai lake sediments.