Fates of intracellular and extracellular antibiotic resistance genes during the cattle farm wastewater treatment process

• Published in: Bioresource technology Vol. 344; no. Pt B; p. 126272
• Main Authors: Liang, Chengyu, Wei, Dong, Yan, Weizhi, Zhang, Siying, Shi, Jiping, Liu, Li
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.01.2022
• Subjects: Animals; Anti-Bacterial Agents - pharmacology; Antibiotic resistance gene (ARG); Bacterial community; Cattle; Cattle farm wastewater; Drug Resistance, Microbial - genetics; Extracellular ARG; Farms; Genes, Bacterial - genetics; Intracellular ARG; Waste Water - analysis; Water Purification; Extracellular ARG; Cattle farm wastewater; Antibiotic resistance gene (ARG); Bacterial community; Intracellular ARG
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2021.126272

•Concentration of iARGs was one order of magnitude higher than that of eARGs in raw wastewater.•iARGs and eARGs were gradually reduced by UASB, A2O2, MBR and ozone disinfection.•Concentration of iARGs was two orders of magnitude lower than that of eARGs in effluent.•ARGs were positively correlated with almost all water quality indicators.•Bacteroidetes, Firmicutes and Spirochaetes may be main iARGs hosts in cattle farm WWTP. Cattle farm wastewater, as a significant reservoir for antibiotic resistance genes (ARGs), has received wide attention. Intracellular and extracellular ARGs (iARGs and eARGs) were detected during wastewater treatment, including solid–liquid separation, anaerobic regulation, upflow anaerobic sludge blanket (UASB) digestion, an anoxic–oxic-anoxic–oxic (A2O2) process, a membrane bioreactor (MBR), and ozone disinfection. Ten abundant ARGs were chosen as the target ARGs according to metagenomic sequencing. The concentrations of the total target iARGs and eARGs were 6.12 × 107 and 3.24 × 106 copy numbers/mL in raw wastewater, and then 3.79 × 103 and 3.95 × 105 copy numbers/mL in final effluent, because UASB, A2O2, MBR and ozone disinfection can gradually reduce the concentrations of most ARGs. The concentrations of ARGs were positively correlated with almost all wastewater quality indicators. Positive correlation was also observed between iARGs and Bacteroidetes, Firmicutes and Spirochaetes, indicating that the bacteria in these three phyla might be the main hosts of ARGs. Wastewater quality indicators and bacterial community composition affected the distribution and removal of ARGs during cattle wastewater treatment.