Context.Microorganisms in wastewater treatment plants (WWTPs) are essential for water purification to protect public and environmental health. The diversity andassembly of bacterial communities in wastewater treatment plants (WWTPs) is thought to have a direct influence on system performance.
Gap.Scientific understanding of activated sludge bacterialcommunity assembly is lacking in industrial wastewater treatment plants systems (IWWTPs).
Aim.We compared and analyzed the bacterial community diversity, structure and assembly in anoxic and aerobic tanksthe activated sludge from twoIWWTPs.
Methods.We analysed the 16S rRNA gene sequences from two IWWTPs (Guobang Pharmaceutical and Longsheng Dyestuff IWWTPs) located in a typical industrial park, southeastern China.
Findings.The results showed that bacteria from pharmaceutical and dyestuff IWWTPs exhibited contrasting community compositions, which might beowing to influenced by different environmental factors and influent water quality.Neutral model and null model bacterial communities in activated sludge in the two IWWTPswere strongly driven by stochastic processes (i.e.dispersal and drift).Molecular ecological network analysis showed thatbacteria tended to co-occur rather than co-exclude. The network topological characteristics and complexity didn't showed significant difference between bacterial communities in two IWWTPs, indicating that the bacterial communities in two IWWTPs have similar species interaction. In the co-occurrence networks, proteobacteria and bacteroidetes were the potential keystone taxa, showing their large influence in the community as "ecosystem engineers".
Utilization.This study demonstrated that stochastic processes are sufficient in shaping activated sludge bacterial communities from IWWTPs.Our findings enhance our mechanistic understanding of the IWWTPs activated sludge bacterial communities and provide important implications forwastewater treatment processes.
Fig. 1: Comparison between community assembly and co-occurrence networks of the activated sludge bacterial communities in different IWWTPs.
Acknowledgement.This work was supported by the National Natural Science Foundation of China (grant numbers 51938001) and Natural Science Foundation of Beijing (Grant No. 8192022)
