No abstract

Purpose The bacterioplankton community is an important part of the lake ecosystem, which not only influences the physical and chemical environmental factors of lake water quality, but also affects the functional processes of the lake ecosystem. However, little is known about the formation and maintenance mechanisms of bacterial plankton diversity and community structure composition in the inland saline-alkali lakes. Methods In this study, the inland saline-alkali lake Daihai was used as the object of study, 9 sampling areas were set up according to the actual situation of Daihai Lake, and 16S rRNA Illumina Miseq™/Hiseq™ high-throughput sequencing technology was applied to study the spatial distribution characteristics of bacterial microbial diversity and community structure composition of lake water bodies and their key influencing factors. Results The bacterioplankton community composition and the relative abundance of each group of bacteria in 9 sample areas of Daihai Lake were high, with the main bacterial taxa at the phylum level being Actinobacteria, Bacteroidetes, Cyanobacteria_Chlorophyceae, Bacteroides, Cyanobacteria_Chloroplast, Bacteroidetes, Firmicutes, unclassified_Bacteria, Proteobacteria and Verrucomicrobia, with a maximum value of 4.14 (DH5) and a minimum value of 3.53 (DH3) for the bacterial community diversity index. Proteobacteria at the phylum level and Sulfurimonas at the genus level were sensitive to the evolution of lake degradation; the water quality physicochemical parameters DO (dissolved oxygen), pH, con(conductivity), TP (total phosphorus), sal(salinity) and TN (total nitrogen) had the most significant effect on the overall bacterial community structure with the highest correlation coefficient, and the Mantel test showed that this correlation was significant. Conclusion The bacterioplankton community structure of the inland saline-alkali lake Daihai is highly variable, and the genus Sulfurimonas plays an important role in the biogeochemical cycling of Daihai Lake waters and should receive more attention in future studies.