Regional discrepancy of microbial community structure in activated sludge system from Chinese WWTPs based on high-throughput 16S rDNA sequencing

Overall understanding of microbial community structure in activated sludge (AS) system at regional level is of great significance for operation regulation of wastewater treatment plants (WWTPs). In this study, 110 AS samples from 21 cities in different Chinese regions were analyzed based on high-throughput 16S ribosomal DNA (rDNA) sequencing to explore effects of different regions on microbial community structure. Results showed that the regions with different characteristics (south and north, coastal and inland, high GDP and low GDP) had great impact on AS bacterial community in China. Core bacterial communities (101 OTUs) in south China were more abundant than those in north China (49 OTUs), and many core species in south China were associated with nutrient removal. Coastal WWTPs possessed unique bacterial communities due to the influence of marine bacteria. Phyla Chloroflexi and Acidobacteria were observed to be main biomarkers in coastal WWTPs. Compared with low GDP regions, more diverse microbial community and effective wastewater treatment were discovered in high GDP regions, and environmental factor analysis suggested that they were mainly correlated with high capacity and influent TP in the WWTPs. β nearest taxon index (βNTI) analysis showed that microbial community assembly in the analyzed AS samples was dominated by deterministic factors (70.67%) and influent quality was observed to be main factor.