Research on seasonal and spatial shifts in river sediments microbial community structure

Based on the important role sediment microorganisms play in material cycle and energy flow of river system, the relationship between sediment microbial community structure and environmental variables was described, and the research on sediments microbial community structure in different water types during different periods was presented using phospholipids fatty acid analysis (PLFA). The results show that the sediments microbial community structures in the same water condition are in sound consistency, and water quality indexes are the main reason for microbial community structure difference between the samples from different water types. In the same water type, microbial biomass of November samples were larger than that of September samples. The sediment microbial community structure under Class IV water changes significantly along time due to G-community changing, while that under Class III water inclines to remain the same along time. Aquatic plants factor corresponds to the phenomenon that sediment microbial community structure difference between the samples from different water types is larger in November than in September. "G^-/G⁺" can finely reflect microbial community structure change responding to water quality index change.