Monochloramine is used to regulate microbial regrowth in drinking water distribution systems (DWDS) but produces carcinogenic disinfection byproducts and constitutes a source of energy for nitrifying bacteria. This study followed biofilm-dispersed microbial communities of a full-scale DWDS distributing ultrafiltered water over three years, before and after removal of monochloramine. Communities were described using flow cytometry and amplicon sequencing, including full-length 16S rRNA gene sequencing. Removal of monochloramine increased total cell counts by up to 440%. Increased abundance of heterotrophic bacteria was followed by emergence of the predatory bacteria Bdellovibrio, and a community potentially metabolizing small organic compounds replaced the nitrifying core community. No increased abundance of Mycobacterium or Legionella was observed. Co-occurrence analysis identified a network of Nitrosomonas, Nitrospira, Sphingomonas and Hyphomicrobium, suggesting that monochloramine supported this biofilm community. While some species expanded into the changed niche, no immediate biological risk to consumers was indicated within the DWDS.

一氯胺用于调节饮用水分配系统 (DWDS) 中的微生物再生，但会产生致癌的消毒副产物，并构成硝化细菌的能量来源。这项研究跟踪了三年多的全尺寸 DWDS 分配超滤水的生物膜分散的微生物群落，在去除一氯胺之前和之后。使用流式细胞术和扩增子测序（包括全长 16S rRNA 基因测序）描述群落。去除一氯胺可使总细胞计数增加高达 440%。异养细菌的丰度增加之后出现了捕食性细菌蛭弧菌，一个可能代谢小有机化合物的群落取代了硝化核心群落。没有增加丰度观察到分枝杆菌或军团菌。共现分析确定了Nitrosomonas、Nitrospira、Sphingomonas和Hyphomicrobium的网络，表明一氯胺支持该生物膜群落。虽然一些物种扩展到变化的生态位，但 DWDS 中没有表明对消费者有直接的生物风险。