Cadmium (II) alters the microbial community structure and molecular ecological network in activated sludge system. (December 2019)

• Record Type: Journal Article
• Authors: Wang, Xiaohui; Ya, Tao; Zhang, Minglu; Liu, Lin; Hou, Pengfei; Lu, Shaoyong
• Is Part Of: Environmental pollution. Volume 255(2019)Part 2
• Publication Date: 2019-12
• Subjects: Cadmium (II) -- Activated sludge system -- Microbial community structure -- Molecular ecological network; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2019.113225
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Cadmium (II) can potentially alter the microbial community structure and molecular ecological network in activated sludge systems. In this study, we used Illumina sequencing combined with an RMT-based network approach to show the response of the microbial community and its network structure to Cd (II) in activated sludge systems. The results demonstrated that 1 mg/L Cd (II) did not have chronic negative effects on chemical oxygen demand (COD) reduction and denitrification processes, but negatively affected the nitrification process and phosphorus removal. In contrast, 10 mg/L Cd (II) adversely affected both COD and nutrient removal, and reduced the microbial diversity and changed the overall microbial community structure. The relative abundances of Nitrosomonadaceae, Nitrospira, Accumulibacter and Acinetobacter, which are involved in nitrogen removal, significantly decreased with increases in the Cd (II) concentration. In addition, molecular ecological network analysis showed that the networks sizes in the presence of higher levels of Cd (II) were smaller than in the control, but the nodes were more closely connected with neighbors. These shifts in bacterial abundance and the bacterial network structure may be responsible for the deterioration of COD and nutrient removal. Overall, this study provides new insights into the effects of Cd (II) on the bacterial community and its interactions in activated sludge systems. Graphical abstract: Image 1 Highlights: Cd (II) altered the overall bacterial community structure. Cd (II) decreased the network size but induced to higher network complexity. Cd (II) had different effects on the microbial interaction of Proteobacteria and Saccharibacteria.