TEMPORAL AND SPATIAL VARIATION CHARACTERISTICS AND DRIVING FACTORS OF BACTERIAL COMMUNITY STRUCTURE IN BAO’AN LAKE

To explore the temporal and spatial variation characteristics and driving factors of bacterial community structure in Bao’an Lake, water samples were collected in spring, summer, autumn and winter of 2019 in Bao’an Lake, and the composition and diversity of bacterial community in surface water of Bao’an Lake were studied using metagenomic sequencing. The results showed that: (1) There was no significant difference in bacterial community structure among different lake areas. The Richness index, Pielou index, Shannon index and Simpson index in summer and autumn were significantly higher than those in spring and winter (P<0.05). The dominant phyla in summer and autumn were Proteobacteria, Actinobacteria and Cyanobacteria, while in spring and winter, the dominant plyla were Proteobacteria and Actinobacteria; (2) Temperature, transparency, pH, dissolved oxygen, COD_Mn, Chl.a, and total phosphorus were main driving factors accounting for the temporal and spatial of bacterial community structure in Bao’an Lake; (3) The assembly process of bacterial community in Bao’an Lake was dominated by stochastic process in spring, summer and autumn, while deterministic process dominated in winter; (4) The bacterial network interactions in Bao’an Lake had obvious seasonal characteristics: the bacterial interspecific interaction in Bao’an Lake was becoming closer and more complex from spring to winter. In conclusion, the seasonal variation characteristics of the bacterial community structure of Bao’an lake is obvious, and the factors such as temperature, transparency, pH, dissolved oxygen and COD_Mn have the potential to shape the bacterial community structure. This study provides the basis for understanding the spatial-temporal characteristics of bacterial community and driving factors in freshwater lakes.