密云水库细菌群落组成结构及影响因素

As the largest reservoir in North China, the Miyun Reservoir is the most important surface drinking water source in Beijing. Bacteria are key regulators of reservoir ecosystem structure and function, and exploring the community distribution characteristics of bacteria is important for maintaining water quality safety in reservoirs. The spatiotemporal distribution and environmental factors of bacterial communities in the water and sediment of the Miyun Reservoir were explored using the high-throughput sequencing method. The results showed a higher a-diversity and non-significant seasonal variation of the bacterial community in the sediment, and the abundant sedimental species were affiliated with Proteobaeteria. For planktonie bacteria, Actinobacteriota was the dominant phylum, and the seasonal variance was represented by CL500-29_marine _group and hgcl_clade in the wet season and Cyanobium_PCC-6307 in the dry season. Additionally, obvious differences in key species were also found in water and sediment, and more indicator species were obtained in sedimental bacteria. Further, a more complex co-existence network was identified in water compared to that in sediment, indicating the strong ability of planktonie bacteria to resist environmental changes. Environmental factors had a significantly higher effect on the bacterial community of the water column than that of the sediment. Furthermore, SO^2-₄and TN were the main factors affecting planktonie bacteria and sedimental bacteria, respectively. These findings revealed the distribution patterns and driving forces of the bacterial community in the Miyun Reservoir, which will provide important guidance for reservoir management and water-quality assurance.