Response of microbial interactions in activated sludge to chlortetracycline. (1st November 2022)

• Record Type: Journal Article
• Authors: He, Wenshan; Fan, Jingkai; Ya, Tao; Zhang, Minglu; Zhang, Tingting; Wang, Xiaohui
• Is Part Of: Environmental pollution. Volume 312(2022)
• Publication Date: 2022-11-01
• Subjects: Chlortetracycline -- Activated sludge system -- Microbial interaction -- 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.2022.120035
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Chlortetracycline (CTC) has attracted increasing attention due to its potential environmental risks. However, its effects on bacterial communities and microbial interactions in activated sludge systems remain unclear. To verify these issues, a lab-scale sequencing batch reactor (SBR) exposed to different concentrations of CTC (0, 0.05, 0.5, 1 mg/L) was carried out for 106 days. The results showed that the removal efficiencies of COD, TN, and TP were negatively affected, and the system functions could gradually recover at low CTC concentrations (≤0.05 mg/L), but high CTC concentrations (≥0.5 mg/L) caused irreversible damage. CTC significantly altered bacterial diversity and the overall bacterial community structure, and stimulated the emergence of many taxa with antibiotic resistance. Molecular ecological network analysis showed that low concentrations of CTC increased network complexity and enhanced microbial interactions, while high concentrations of CTC had the opposite effect. Sub-networks analysis of dominant phyla (Bacteriodota, Proteobacteria, and Actionobacteriota) and dominant genera ( Propioniciclava, a genus from the family Pleomorphomonadaceae and WCHB1-32) also showed the same pattern. In addition, keystone species identified by Z-P analysis had low relative abundance, but they were important in maintaining the stable performance of the system. In summary, low concentrations of CTC enhanced the complexity and stability of the activated sludge system. While high CTC concentrations destabilized the stability of the overall network and then caused effluent water quality deterioration. This study provides insights into our understanding of response in the bacteria community and their network interactions under tetracycline antibiotics in activated sludge system. Graphical abstract: Image 1 Highlights: Low chlortetracycline concentrations (≤0.05 mg/L) didn't affect system functions. High chlortetracycline concentrations (≥0.5 mg/L) deteriorated system performance. Low chlortetracycline concentrations increased network complexity. High chlortetracycline concentrations reduced microbial interactions. Chlortetracycline increased bacterial diversity and altered community structure.