Biofilms were one of the main habitats of microbes in the drinking water distribution system. The variation of environmental conditions can lead to the detachment of biofilms and the deterioration of water quality. In this study, the effects of disinfectant exposure and starvation treatment on the detachment of biofilms were investigated. The results showed that detaching rate increased with the concentration of chloramine in the inlet water and 1.0 mg/L of chloramine led to the largest detached biomass. The starvation treatment resulted in less biofilm biomass but the detaching rates of treated biofilms were higher than those without starvation. The 16S rRNA sequencing results showed that detached and stubborn biofilms had a significant difference in microbial diversity and richness. The microbial community composition of the two types of biofilm showed the difference in the abundance of Nitrospira, Bryobacter, Hyphomicrobium, and Pedomicrobium. Chloramine exposure did not have a significant impact on the microbial community while the starvation treatment led to a higher abundance of chemolithotrophs bacteria. Metagenomic results indicated that detached biofilms had higher abundances of ARGs and starvation treatment could enrich the ARGs. The results of this research could provide the knowledge of biofilm sloughing and help understand the health risk of antibiotic resistance in drinking water.

生物膜是饮用水分配系统中微生物的主要栖息地之一。环境条件的变化会导致生物膜的脱落和水质的恶化。在这项研究中，研究了消毒剂暴露和饥饿处理对生物膜分离的影响。结果表明，分离速率随着进水氯胺浓度的增加而增加，1.0 mg/L的氯胺导致最大的分离生物量。饥饿处理导致生物膜生物量减少，但处理过的生物膜的分离率高于未饥饿处理的生物膜。16S rRNA测序结果表明，分离的和顽固的生物膜在微生物多样性和丰富度方面存在显着差异。Nitrospira、Bryobacter、Hyphomicrobium和Pedomicrobium。氯胺暴露对微生物群落没有显着影响，而饥饿处理导致化学无机营养菌的丰度更高。宏基因组结果表明，分离的生物膜具有更高的 ARG 丰度，饥饿处理可以丰富 ARG。这项研究的结果可以提供生物膜脱落的知识，并有助于了解饮用水中抗生素耐药性的健康风险。