中文摘要：

为了更准确地研究管网水中细菌的稳定性,利用流式细胞术（Flow cytometry,FCM）和异养菌平板计数法（Heterotrophic plate count,HPC）检测北京市12处管网末梢水中细菌数量,并将两种方法的检测结果进行对比.进一步将FCM应用于细菌的再生长潜能和一天中细菌稳定性的研究中.结果显示,HPC对12处管网水中细菌的检测结果在0-23 CFU/m L间,而FCM测得活细菌数为2.2×10^3-1.6×10^4 cells/m L,细菌总数在22℃下培养7 d能生长到10^6-10^7 cells/m L.一天中不同时间用水量不同,细菌总数也不同.本研究表明,FCM测定方法明显优于HPC法,且能够快速准确地反映细菌的再生长潜能及短时间内细菌的稳定性特征.

英文摘要：

This research investigated the drinking water distribution system of Beijing for the bacterial stability in chlorinated drinking water.Flow cytometry（FCM） and heterotrophic plate counts（HPC） methods were used to evaluate the drinking water quality and stability of 12 water samples throughout the distribution network.The samples were incubated at 22 ℃without shaking;total cell counts and percentages of intact cells measurements were done by FCM daily during 7 consecutive days.Another detailed assessment of dynamic changes was done at 1-hour intervals at 8 am- 8 pm in each day.The results showed FCM intact cell concentrations varying from 2.2 × 10^3 cells/mL to 1.6×10^4 cells/mL in the network,while HPC results varying from 0 CFU/mL to 23 CFU/mL.The average total cell counts at the end of the 7-day cultivation for all samples were approximately 10^6- 10^7 cells/mL.High frequency monitoring of a single sampling point demonstrated temporal instability in the network.This research obtained some data by FCM that was not detectable by HPC.We understand it as that FCM is suitable for monitoring the biological stability and regrowth potential of bacteria in drinking water systems.