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Updated: Jan 30, 2026

Microbial Communities in Nature and Laboratory - Interview
Published on: May 28, 2007
Effect of sequential UV/free chlorine disinfection on opportunistic pathogens and microbial community structure in
Lizhong Liu1, Xueci Xing2, Chun Hu3
1Key Laboratory of Aquatic Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang City, Jiangxi 330013, China; School of Water Resource and Environmental Engineering, East China University of Technology, Nanchang City, Jiangxi 330013, China.
Abstract:
Drinking water distribution systems (DWDS) may be a "Trojan Horse" for some waterborne diseases caused by opportunistic pathogens (OPs). In this study, two simulated DWDS inoculated with groundwater were treated with chlorine (Cl2) and ultraviolet/chlorine (UV/Cl2) respectively to compare their effects on the OPs distributed in four different phases (bulk water, biofilms, corrosion products, and loose deposits) of DWDS. 16S rRNA genes sequencing and qPCR were used to profile microbial community and quantify target genes of OPs, respectively. Results showed that UV/Cl2 was more effective than single Cl2 to control the regrowth of OPs in the water with the same residual chlorine concentration. However, the OPs inhabiting the biofilms, corrosion products, and loose deposits seemed to be tolerant to UV/Cl2 and Cl2, demonstrating that OPs residing in these phases were resistant to the disinfection processes. Some significant microbial correlations between OPs and Acanthamoeba were found by Spearman correlative analysis (p < 0.05), demonstrating that the ecological interactions may exist in the DWDS. 16S rRNA genes sequencing of water samples revealed a significant different microbial community structure between UV/Cl2 and Cl2. This study may give some implications for controlling the OPs in the DWDS disinfected with UV/Cl2.
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