CHARACTERISTICS OFTHE MICROBIAL COMMUNITY IN SURFACE WATER AND SEDIMENTOFTHE CHANGCHUN SECTION OF YITONG RIVER

摘要

Yitong River is the main river flowing through Changchun City nonetheless has been polluted seriously in recent years.The characteristics of the microbial community can indicate the current situation of river pollution.Hence,the characteristics of the microbial community in surface water and sediment in the Yitong River (Changchun City) were analyzed by high-throughput sequencing technology based on 16SrRNA Gene at different periods.The results showed that the dominant microorganisms at the Phylum level were Proteobacteria,Actinobacteria and Bacteroides accounting for 73.5%.The composition of the upstream and downstream microbial species was similar in different periods.In the same sampling sites,there were significant differences in the genera of microorganisms in surface water and sediments.The relative abundance of Hgcl_clade was comparatively high in the water samples,while Flavobacterium was abundant in sediments.A total of 940,437 sequences were detected in the water samples and sediment samples,and the microbial sequences were the highest in August,which were approximately the same in April and November.The diversity index and richness index showed that the microbial community in sediments was significantly higher than that in the corresponding water,and the microbial community diversity and richness were higher in August.The PICRUSt functional gene prediction showed that there were many metabolism-related genes in the water which could lead to a greater risk of neurodegenerative diseases and infectious diseases in humans and a greater impact on the endocrine system of organisms.The results of redundancy analysis (RDA) showed that pH,dissolved oxygen (DO),total nitrogen (TN),NH4+-N,chlorophyll a,Zn and Cd significantly elucidated 57.02% of the microbial community composition in the water sample,whiles the heavy metals Cu,Zn,Cr and Pb elucidated 29.01% of the microbial community composition in the sediment.Among them,pH,DO,TN,chlorophyll a,Cd and other environmental factors had the greatest impact on the microbial community structure.