Microbial Characterization Of Beijing Drinking Water By Flow Cytometry And Miseq Sequencing

Microorganisms are commonly found in the water distribution systems. The conventional plate method has many disadvantages for detecting microbes in drinking water. The first, in this research, flow cytometry (FCM) was used to evaluate the drinking water stability of 12 water samples throughout the distribution network; Secondly, MiSeq sequencing technology was used to compare microbial communities between urban and suburb water; At last. Pathogenic microorganisms were quantified, and the combined FCM total bacteria concentrations and MiSeq sequencing to determine the relative abundance of pathogenic bacteria resulted in the quantitative evaluation of opportunistic pathogenic bacteria, in addition,100L tap water coming from the urban distribution network was run through Hollow-fiber ultrafiltration, membrane filtration and centrifugation in sequence to concentrate rotavirus, then the PMA-qPCR method was developed to detect activated rotavirus. The following conclusions could be reached:Compared heterotrophic plate count (HPC) with FCM, the results showed HPC varying from 0 CFU/mL to 23 CFU/mL in the network, while FCM intact cell concentrations varying from 2.2×103 cells/mL to 1.6×104 cells/mL. The average total cell counts at the end of the 7-day cultivation for all samples were approximately 106～107 cells/mL. The total cell concentrations varied according to the water consumption. Our research showed that FCM was suitable for monitoring the biological stability and regrowth potential of bacteria in drinking water systems.Compared microbial communities between urban and suburb water, the Proteobacteria were the most abundant phylum, accounting for 42.3%～76.9% of all detected OTUs in urban water samples while 55.5%-87.6% in suburb. On the whole, the number of microorganisms species which can be categorized in suburban water was more than that in urban water, and complexity of microbial in urban water was higher than that in suburban water. Most significantly different species were common type of bacteria living water in urban water, while were intestinal and pathogenic bacteria in suburb. Compared to urban, suburban water have more obvious core microbial communities.The Mycobacteriwn, Corvnebacleiium, and Pseudomonas were detected in urban drinking water distribution systems. The combined FCM and MiSeq sequencing were not only qualitative but also quantitative. In addition. Three filters were efficient for concentrate rotavirus. The samples B,G and J showed positive result of activated rotavirus. Knowledge regarding the concentration of opportunistic pathogenic bacteria and activated rotavirus will be particularly useful for assessing the health risk of drinking water and prevention of gastrointestinal disease outbreaks.