Comparison of particle-associated bacteria from a drinking water treatment plant and distribution reservoirs with different water sources

“This study assessed the characteristics of and changes in the suspended particles and the associated
bacteria in an unchlorinated drinking water distribution system and its reservoirs with different water
sources. The results show that particle-associated bacteria (PAB) were present at a level of 0.8–4.5 × 10³
cells ml−1 with a biological activity of 0.01–0.04 ng l−1 ATP. Different PAB communities in the waters
produced from different sources were revealed by a 16S rRNA-based pyrosequencing analysis. The
quantified biomass underestimation due to the multiple cells attached per particle was ≥ 85%. The
distribution of the biologically stable water increased the number of cells per particle (from 48 to 90) but
had minor effects on the PAB community. Significant changes were observed at the mixing reservoir.
Our results show the characteristics of and changes in suspended PAB during distribution, and highlight
the significance of suspended PAB in the distribution system, because suspended PAB can lead to
a considerable underestimation of biomass, and because they exist as biofilm, which has a greater
mobility than pipe-wall biofilm and therefore presents a greater risk, given the higher probability that it
will reach the customers’ taps and be ingested.”
(Citaat: Liu, G., Ling, F.Q., Mark, E.J. van der, Zhang, X.D., Knezev, A., Verberk, J.Q.J.C., Meer, W.G.J. van der, Medema, G.J., Liu, W.T., Dijk, J.C. van Comparison of particle-associated bacteria from a drinking water treatment plant and distribution reservoirs with different water sources – Scientific Reports 6(2016), art.no.20367 – Open Access)