Microbial biogeography of drinking water: patterns in phylogenetic diversity across space and time. BioD Project

In this study we collected water from different locations in 32 unchlorinated drinking water distribution networks in the Netherlands and analysed the spatial and temporal variation in microbial community composition by high-throughput sequencing (using Roche 454 and Illumina MiSeq) of barcoded V4-16S rRNA gene amplicons. We observed that microbial community compositions of raw source water and processed water were very different for each distribution network sampled. Although, in each network, major differences in community compositions were observed between raw and processed water, the community structure of processed water did not differ substantially from end-point tap water. Different end-point water samples within the same distribution network revealed very similar community structures. These network specific community structures were shown to be surprisingly stable in time. Our findings demonstrate that the high-throughput sequencing approach applied provides a powerful and sensitive tool to assess and evaluate microbial community composition in drinking water distribution systems. Furthermore, this approach can be used to quantitatively compare the microbial communities to match an end-point water sample to a specific distribution network. Insight in the microbial ecology of drinking water distribution systems will facilitate the development of effective control strategies that will ensure safe and high-quality drinking water.