Response of extracellular polymeric substances and microbial community structures on resistance genes expression in wastewater treatment containing copper oxide nanoparticles and humic acid

• Published in: Bioresource technology 2021-11, Vol.340, p.125741-125741, Article 125741
• Main Authors: Li, Yu, Wang, Jing, Li, Bingyan, Geng, Mengdan, Wang, Yan, Zhao, Jianguo, Jin, Baodan, Li, Yanfei
• Format: Article
• Language: English
• Subjects: CuO NPs; Extracellular polymeric substances; Humic acid; Microbial community structures; Resistance genes expression
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2021.125741

•Humic acid addition did not affect the pollutants removal under CuO NPs stress.•Resistance genes expression was related to EPS secretion and microbial community.•Humic acid could reduce the resistance genes expression in wastewater treatment. The extracellular polymeric substances (EPS) and microbial community structures were investigated in wastewater treatment containing copper oxide nanoparticles (CuO NPs) (reactor R1) and CuO NPs and humic acid (HA) (reactor R2) using both sequencing batch bioreactors (SBRs), and their response on resistance genes expression was analyzed. The removal of influent chemical oxygen demands (COD) and NH4+-N was moderately influenced under CuO NPs (5 mg/L) stress, while the function of HA (10 mg/L) was not reflected. However, the EPS production and microbial community were affected by the HA addition. The expression of different antibiotic resistance genes (ARGs), metal-resistance genes (MRGs), and intI1 was related to the primary compositions of polysaccharides and proteins in EPS and different microbial communities at the genus level. Furthermore, the expression of resistance genes was not stimulated under CuO NPs stress, and supplying HA was suggested to reduce their expression in wastewater treatment.