Molecular analysis of long-term biofilm formation on PVC and cast iron surfaces in drinking water distribution system

Abstract

a b s t r a c tTo understand the impacts of different plumbing materials on long-term biofilm formation in water supply system, we analyzed microbial community compositions in the bulk water and biofilms on faucets with two different materials-polyvinyl chloride (PVC) and cast iron, which have been frequently used for more than10 years. Pyrosequencing was employed to describe both bacterial and eukaryotic microbial compositions. Bacterial communities in the bulk water and biofilm samples were significantly different from each other. Specific bacterial populations colonized on the surface of different materials. Hyphomicrobia and corrosion associated bacteria, such as Acidithiobacillus spp., Aquabacterium spp., Limnobacter thiooxidans, and Thiocapsa spp., were the most dominant bacteria identified in the PVC and cast iron biofilms, respectively, suggesting that bacterial colonization on the material surfaces was selective. Mycobacteria and Legionella spp. were common potential pathogenic bacteria occurred in the biofilm samples, but their abundance was different in the two biofilm bacterial communities. In contrast, the biofilm samples showed more similar eukaryotic communities than the bulk water. Notably, potential pathogenic fungi, i.e., Aspergillus spp. and Candida parapsilosis, occurred in similar abundance in both biofilms. These results indicated that microbial community, especially bacterial composition was remarkably affected by the different pipe materials (PVC and cast iron).

Influence of hydraulic regimes and Cl2/NH3-N mass ratios on the bacterial structure and composition in an experimental flow cell chloraminated drinking water system

“…This group is always considered as the opportunistic pathogens, and it is the most frequent causative agent of drinking water related disease outbreaks 57 . Other abundant genera species in this study, such as Gemmata and Porphyrobacter have been observed in drinking water samples and suggested to be adapted to oligotrophic conditions in DWDSs [58][59][60] . In addition, Azospira, which belongs to denitrifying genus 61 , was detected to be abundance as well.…”

Bacteria in drinking water sources of a First Nation reserve in Canada

“…The viable cells in the water leaving the WTP were dominated by Gammapoteobacteria (Fig 3), particularly members of Xanthomonadales order (Table 1), while the enrichment of viable Alphaproteobacteria in homes with piped and cistern water (Fig 3) indicates that biofilms are present on the inner surfaces of pipes and cisterns in the water distribution system of this community (Mathieu et al, 2009;Henne et al, 2012;Liu et al, 2014).…”

Environmental (Saprozoic) Pathogens of Engineered Water Systems: Understanding Their Ecology for Risk Assessment and Management

“…A further influencing factor of biofilm community structure is the substratum (e.g. pipe material); for example, with generally greater biofilm growth on plastic pipes compared to copper, which, despite less biofilm copper may support members more likely to increase legionellae presence [ 48 , 49 , 50 ]. While expected, only recently have studies identified a further nuance of engineered water system biofilms, temporal dynamics of biofilm members due to changes in hydraulics and water chemistries [ 51 , 52 ].…”