A microbiology-based multi-parametric approach towards assessing biological stability in drinking water distribution networks
Vrouwenvelder, Johannes S.
Hammes, Frederik A.
KAUST DepartmentWater Desalination and Reuse Research Center (WDRC)
Environmental Science and Engineering Program
MetadataShow full item record
AbstractBiological stability of drinking water implies that the concentration of bacterial cells and composition of the microbial community should not change during distribution. In this study, we used a multi-parametric approach that encompasses different aspects of microbial water quality including microbial growth potential, microbial abundance, and microbial community composition, to monitor biological stability in drinking water of the non-chlorinated distribution system of Zürich. Drinking water was collected directly after treatment from the reservoir and in the network at several locations with varied average hydraulic retention times (6-52h) over a period of four months, with a single repetition two years later. Total cell concentrations (TCC) measured with flow cytometry remained remarkably stable at 9.5 (±0.6)×104cells/ml from water in the reservoir throughout most of the distribution network, and during the whole time period. Conventional microbial methods like heterotrophic plate counts, the concentration of adenosine tri-phosphate, total organic carbon and assimilable organic carbon remained also constant. Samples taken two years apart showed more than 80% similarity for the microbial communities analysed with denaturing gradient gel electrophoresis and 454 pyrosequencing. Only the two sampling locations with the longest water retention times were the exceptions and, sofar for unknown reasons, recorded a slight but significantly higher TCC (1.3(±0.1)×105cells/ml) compared to the other locations. This small change in microbial abundance detected by flow cytometry was also clearly observed in a shift in the microbial community profiles to a higher abundance of members from the Comamonadaceae (60% vs. 2% at other locations). Conventional microbial detection methods were not able to detect changes as observed with flow cytometric cell counts and microbial community analysis. Our findings demonstrate that the multi-parametric approach used provides a powerful and sensitive tool to assess and evaluate biological stability and microbial processes in drinking water distribution systems. © 2013 Elsevier Ltd.
SponsorsWe would like to thank Fangqiong Ling, and Hideyuki Tamaki for their help with the microbial community analysis. We are grateful to the financial support of the EU project TECHNEAU (018320).
- Flow cytometry total cell counts: a field study assessing microbiological water quality and growth in unchlorinated drinking water distribution systems.
- Authors: Liu G, Van der Mark EJ, Verberk JQ, Van Dijk JC
- Issue date: 2013
- Overnight stagnation of drinking water in household taps induces microbial growth and changes in community composition.
- Authors: Lautenschlager K, Boon N, Wang Y, Egli T, Hammes F
- Issue date: 2010 Sep
- Flow cytometry for fast microbial community fingerprinting.
- Authors: De Roy K, Clement L, Thas O, Wang Y, Boon N
- Issue date: 2012 Mar 1
- Flow-cytometric total bacterial cell counts as a descriptive microbiological parameter for drinking water treatment processes.
- Authors: Hammes F, Berney M, Wang Y, Vital M, Köster O, Egli T
- Issue date: 2008 Jan
- Monitoring microbiological changes in drinking water systems using a fast and reproducible flow cytometric method.
- Authors: Prest EI, Hammes F, Kötzsch S, van Loosdrecht MC, Vrouwenvelder JS
- Issue date: 2013 Dec 1