SEASONAL VARIATION CHARACTERISTICS OF MICROBIAL COMMUNITIES IN THE SEDIMENTS OF URBAN BLACK-ODOROUS RIVER IN LOWER REACHES OF SHAYING RIVER

In order to study the seasonal variation characteristics of microbial communities in the sediments of the black-odorous river located in lower reaches of Shaying River, high-throughput sequencing approach was used to sequence the 16S rDNA gene of surficial sediments from the Zhongqing River and the Qiyu River. The results showed that microbial species diversity in urban black-odorous river was not high and changed with different seasons: spring > winter ≥ summer > autumn. The redundancy analysis revealed that the microbial diversity was significantly affected by the season and pH of the sediment. By analyzing the microbial community structure in sediment at phylum level, it is found that seasons, temperature, TN and SOM have a great impact on the microbial population. The relative abundance of dominant bacteria such as Proteobacteria, Firmicutes, Chloroflexi, Verrucomicrobia, Bacteroidetes and Actinobacteria differed at the seasonal level. The relative abundances of Firmicutes, Chloroflexi, Actinobacteria and Acidobacteria in spring were relatively high, while Proteobacteria was relatively low. The relative abundances of Verrucomicrobia and Bacteroidetes in autumn dramatically decreased, but Proteobacteria increased significantly compared with other seasons. A total of 16 sulfate-reducing bacteria genus were detected in all samples, among which Desulfoprunum was the most abundant. SRB was the most abundant in spring with the highest relative abundance. SRB was positively correlated with \rmSO_4^2 - , TN, SOM, Cl^– etc. The above results provide a reference for the selection of control time to effectively avoid the generation of black and odorous substances in rivers.