Microbial communities play an important role in water quality regulation and biogeochemical cycling in freshwater ecosystems. However, there is a lack of research on the seasonal variation in lake water microorganisms in cold environments. In this study, 16S rRNA gene high-throughput sequencing was used to explore the microbial community and its influencing factors in Hulun Lake water during different seasons. The results showed that Proteobacteria, Actinobacteria, and Bacteroidetes were the most important phyla in the microbial community of Hulun Lake, but they had significant seasonal differences in their distribution. In addition, significant seasonal differences were observed in the α diversity of microorganisms, with bacterial diversity being higher in winter than in summer. Changes in environmental variables were significantly correlated with changes in the microbial community, and the rapid changes in temperature, pH, and dissolved oxygen are potentially the major factors influencing seasonal bacterial diversity trends. The findings of the present study enhance our understanding of the microbial communities in alpine lake ecosystems and are of great significance for the management and protection of lake ecosystems.

微生物群落在淡水生态系统的水质调节和生物地球化学循环中发挥着重要作用。然而，目前缺乏对寒冷环境下湖水微生物季节性变化的研究。本研究采用16S rRNA基因高通量测序技术，探讨不同季节呼伦湖水体微生物群落及其影响因素。结果表明，变形菌门、放线菌门和拟杆菌门是呼伦湖微生物群落中最重要的门，但它们的分布存在显着的季节性差异。此外，微生物的α多样性存在显着的季节性差异，冬季细菌多样性高于夏季。环境变量的变化与微生物群落的变化显着相关，温度、pH值和溶解氧的快速变化可能是影响季节性细菌多样性趋势的主要因素。本研究的结果增进了我们对高山湖泊生态系统微生物群落的认识，对湖泊生态系统的管理和保护具有重要意义。