RESEARCH ARTICLE

Metagenomic insights into the variation of bacterial communities and potential pathogenic bacteria in drinking water treatment and distribution systems

¹ State Key Laboratory of Pollution Control and Resource Reuse, Environmental Health Research Center, School of the Environment, Nanjing University Nanjing 210023 China
² China Three Gorges Construction Engineering Corporation Beijing 100048 China
³ Nanjing Foreign Language School Nanjing 210008 China

^* Corresponding authors: (emails: jiasy@nju.edu.cn (Shuyu Jia); zhangxx@nju.edu.cn (Xu-Xiang Zhang))

Received: 21 February 2022
Revised: 6 April 2022
Accepted: 11 April 2022

Abstract

High-throughput sequencing of 16S rRNA gene amplicons was conducted to characterize the changing patterns of bacterial community and potential pathogens in full-scale drinking water treatment and distribution systems. Results showed that Actinobacteria was the predominant phylum in source water, while Proteobacteria dominated after chlorine disinfection and its relative abundance increased from 40.88%±9.45% to 67.86%±27.10%. The genera Pseudarthrobacter, Arenimonas, and Limnohabitans were effectively removed by chlorination, while Phreatobacter, Undibacterium, Pseudomonas, and Sphingomonas within the Proteobacteria phylum were greatly enriched after chlorination. Metagenomic analyses revealed the occurrence of 56 species of potential pathogenic bacteria within 17 genera in drinking water, mainly including Pseudomonas fluorescens and five mycobacteria species, which were also persistent in tap water samples. The bacteria were found to be involved in various pathways, among which considerable groups were related to human diseases, including infectious diseases and even cancers.