STUDY ON THE INFLUENCE OF WATER POLLUTION ON THE CHANGES OF MICROBIAL COMMUNITY

This research takes a certain polluted section of Danjiangkou Reservoir as the research object. First, perform SS and COD determinations on the collected water samples, extract DNA from planktonic microorganisms and attached microorganisms, and then perform conventional PCR on 16SrDNA that is highly conserved and maintains a highly "family specific" sequence or structure during the long-term evolution of microorganisms. Amplification and purification. Through the detection of the absolute number of microorganisms, the identification of species, and the routine tests of the water quality of the contaminated river section, the relationship between the species of microorganisms and the spatial change of water quality is explored, reflecting the effect of microorganisms on water purification from another perspective. The research results show that: in a certain pollution section, the structure of attached microorganisms is relatively simple; the upstream has been polluted. The plankton microorganisms multiply in the area of 50-100 m in the vertical direction and 20-90 m in the horizontal direction, and the number of attached microorganisms peaks at 100 m downstream, which is 46.1 mu g/mu l. The TN content exceeds 1.00 mg/L, which is the IV standard for surface water. The correlation analysis between bacterial communities and environmental factors showed that TN (R=-0.7523, P=0.001 is an important factor affecting the distribution of bacteria. Firmicutes (R-0.671, P=0.006), Planctomycetes (R=0.709, P=0.003) was positively correlated with TN, and Actinobacteria was positively correlated with NH4-N (R=0.582, P=0.023).