Flow Cytometry Total Cell Counts: A Field Study Assessing Microbiological Water Quality and Growth in Unchlorinated Drinking Water Distribution Systems

Abstract

The objective of this study was to evaluate the application of flow cytometry total cell counts (TCCs) as a parameter to assess microbial growth in drinking water distribution systems and to determine the relationships between different parameters describing the biostability of treated water. A one-year sampling program was carried out in two distribution systems in The Netherlands. Results demonstrated that, in both systems, the biomass differences measured by ATP were not significant. TCC differences were also not significant in treatment plant 1, but decreased slightly in treatment plant 2. TCC values were found to be higher at temperatures above 15°C than at temperatures below 15°C. The correlation study of parameters describing biostability found no relationship among TCC, heterotrophic plate counts, and Aeromonas. Also no relationship was found between TCC and ATP. Some correlation was found between the subgroup of high nucleic acid content bacteria and ATP (R 2 = 0.63). Overall, the results demonstrated that TCC is a valuable parameter to assess the drinking water biological quality and regrowth; it can directly and sensitively quantify biomass, detect small changes, and can be used to determine the subgroup of active HNA bacteria that are related to ATP.

Evaluation of ATP measurements to detect microbial ingress by wastewater and surface water in drinking water

“…Often total ATP is used as a parameter for microbial activity (van der Wielen & van der Kooij, 2010;Liu et al, 2013a). However, drinking water may contain significant amounts of free ATP (Hammes et al, 2010;Vital et al, 2012).…”

“…ATP measurements can be used for assessing general microbial quality in distributed drinking water (van der Wielen & van der Kooij, 2010), although they are also applicable as a technical parameter of the efficiency of treatments processes at waterworks Vital et al, 2012;Liu et al, 2013a). Moreover, ATP measurements have also been used as a microbiological parameter for assessing regrowth in drinking water (Siebel et al, 2008;Lautenschlager et al, 2010;Vital et al, 2012;Liu et al, 2013a).…”

“…Moreover, ATP measurements have also been used as a microbiological parameter for assessing regrowth in drinking water (Siebel et al, 2008;Lautenschlager et al, 2010;Vital et al, 2012;Liu et al, 2013a). ATP measurements are also used as a monitoring parameter of microbial drinking water quality in the Netherlands (van der Kooij, 2003;van der Wielen & van der Kooij, 2010).…”

Relating Water Quality and Age in Drinking Water Distribution Systems Using Self-Organising Maps

“…Some of the factors influencing HPCs include temperature, residence time within and through the network (water age), disinfection regime and residual disinfectant, organic molecule food sources, flow velocity and patterns, and sediments [19][20][21][22]. HPC only determines a very low percentage (<1% to 10%) of the total bacteria.…”

Using in situ flow cytometry images of ciliates and dinoflagellates for aquatic system monitoring

“…Many authors (Dugenne et al, 2014;Chioccioli et al, 2014;Liu et al, 2013;Graff et al, 2012;Boucher et al, 1991 among others) have developed and used different methods for estimating biomass from flow cytometers. However, due to the skepticism of many yet, the biomass determinations here were based on linear size measurements obtained from cytometric images of living cells.…”