Drinking water distribution systems are increasingly vulnerable to sewage intrusion due to aging water infrastructure and intensifying water stress. While the health risks associated with sewage intrusion have been extensively studied, little is known about the impacts of intruded bacteria and dissolved organic matter (DOM) on microbiology in drinking water. In this dynamic study, we demonstrate that the intrusion of 1 % sewage into tap water resulted in immediate contamination, including an 8-fold increase in biomass (TCC), a 48.9 % increase in bacterial species (ASVs), a 12.5 % increase in organic carbon content (DOC), and a 13.5 % increase in unique DOM molecular formulae. Over time, sewage intrusion altered tap water microbiology by accelerating bacterial growth rates (5-fold faster), selectively promoting ASVs in community succession, and producing 998 more unique DOM formulae. More significantly, statistical analysis revealed that the intrusion of 1 % sewage shifted the driving force of bacterial and DOM composition covariance from a DOM-dependent process in tap water to a bacterial-governed process post-intrusion. Our results clearly demonstrate the disruptive effects of sewage intrusion into tap water, emphasizing the urgent need to consider the long-lasting impacts of sewage intrusion in drinking water distribution systems, in addition to its immediate health risks.

中文翻译：

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污水侵入饮用水的破坏性影响：分子水平的微生物演替和有机转化


由于供水基础设施老化和用水压力加剧，饮用水分配系统越来越容易受到污水侵入的影响。虽然与污水侵入相关的健康风险已得到广泛研究，但对侵入细菌和溶解有机物 （DOM） 对饮用水微生物学的影响知之甚少。在这项动态研究中，我们证明 1% 的污水侵入自来水中会导致直接污染，包括生物量 （TCC） 增加 8 倍，细菌种类 （ASV） 增加 48.9%，有机碳含量 （DOC） 增加 12.5%，以及独特 DOM 分子式增加 13.5%。随着时间的推移，污水入侵通过加速细菌生长速率（快 5 倍）、选择性地促进群落连续的 ASV 以及产生 998 种更独特的 DOM 公式来改变自来水微生物学。更重要的是，统计分析表明，1% 污水的侵入将细菌和 DOM 组成协方差的驱动力从自来水中依赖 DOM 的过程转变为侵入后细菌控制的过程。我们的研究结果清楚地证明了污水侵入自来水的破坏性影响，强调除了其直接的健康风险外，迫切需要考虑污水侵入饮用水分配系统的长期影响。