Spatiotemporal Correlations Between Water Quality And Microbial Community of Typical Inflow River Into Taihu Lake, China
Abstract Changxing River, which is a typical inflow river into the Taihu Lake and occurs severe algae invasion, is selected to study the effect of different pollution sources on the water quality and ecological system. Four types of pollution sources, including the estuary of Taihu Lake, discharge outlets of urban wastewater treatment plants, storm water outlets, and non-point source agricultural drainage areas are chosen, and next-generation sequencing and multi-variate statistical analyses are used to characterize the microbial communities and reveal their relationship with water physicochemical properties. Results showed that ammonia nitrogen (NH4+-N), total nitrogen (TN), and total phosphorus (TP) are the main pollutant in Changxing River, especially at storm water outlets. At the same time, the diversity of microbial communities was the highest in the summer, and dominant phyla included Proteobacteria (40.9%), Bacteroidetes (21.0%) and Euryarchaeota (6.1%) under the condition of algal bloom. Water temperature (T), air pressure (P), concentrations of TP and CODMn were the important variables for the succession of microbial community. From the perspective of different pollution types, relative abundances of Microcystis and Nostocaceae at the estuary of Taihu Lake were correlated positively with dissolved oxygen (DO) and pH, and Pseudomonas and Arcobacter were correlated positively with concentrations of TN and nitrate nitrogen (NO3--N) at storm water outlets. The results provide a reference for the impact of pollution types on river microbial ecosystem under complex hydrological condition and a guidance for the selection of restoration techniques for polluted rivers entering an important lake.