Study on the effect of a tea polyphenol disinfectant on antibiotic resistance genes in drinking water

Abstract

In order to improve the ability of ozone (O₃) and ultraviolet (UV) disinfection processes to remove antibiotic resistance genes (ARGs) and reduce the risk of DBPs, tea polyphenols (TPs) instead of chlorine preparations were used as their auxiliary disinfectant. The effects of O₃-TP and UV-TP on ARGs and the relationship between microbial community change and ARG removal were analyzed by metagenomic sequencing. The results showed that O₃-TP and UV-TP disinfection processes could effectively remove specific types of ARGs and improve the water quality safety of drinking water distribution systems. The reduction of the relative abundances of Acinetobacter, Methylophilus, Acidovorax, Massilia, Sphingopyxis in Proteobacteria, Mycobacterium in Actinobacteria, and Firmicutes by the two disinfection processes was the reason for the decrease in the relative abundances of β-lactam, some aminoglycoside and tetracycline resistance gene subtypes. The wider removal range of ARGs by the O₃-TP disinfection process may be due to its better effect on reducing the microbial diversity of water samples and controlling the relative abundances of Bacteroidetes and Pseudomonas (Proteobacteria) than UV-TP. Tea polyphenols are expected to partially or completely replace chlorine preparations under specific water quality conditions and become the first choice O₃ and UV auxiliary disinfectant.