This study examined how pipe materials and time influence microbial communities in unchlorinated drinking water systems under semi-stagnant conditions. Six common materials—copper, PVC-C, PE-Xb, PE-Xc, PE-100, and PVC-P—were tested alongside glass as a reference control using a modified BPP-test. ATP levels, bacterial community composition, and gene copy numbers of key microorganisms were assessed at multiple time points (1, 4, 8, 12, and 16 weeks). Results revealed that ATP concentrations in both water and biofilm were highest for PVC-P and PE materials, while glass and copper showed the lowest values. Notably, ATP levels peaked early (week 1–4) and stabilized by week 8, indicating that microbial growth reaches equilibrium within eight weeks.
Bacterial community composition evolved significantly over time. At week 1, Betaproteobacteria dominated in both water and biofilm across all materials, but their abundance declined sharply thereafter. In contrast, unclassified Proteobacteria increased over time, suggesting shifts in community structure during colonization. By week 8 and 16, greater diversity emerged, with more bacterial classes exceeding 2% relative abundance compared to earlier stages. CAP and PERMANOVA analyses confirmed that time was a major driver of community change, with samples from week 1 forming a distinct cluster separate from those taken at later time points. However, communities at weeks 8 and 16 were highly similar, reinforcing the conclusion that stability is achieved after eight weeks.
Specific microbial groups showed differential responses to material type and incubation duration.CYB5R1 Antibody Purity Legionella spp.SLC2A4 Antibody web gene copies remained stable in most materials except PE-Xb and PVC-C, where initial spikes occurred.PMID:34727758 For PVC-P, Legionella numbers increased over time, suggesting favorable conditions for its proliferation. V. vermiformis gene copies peaked around week 4 in most materials, though PVC-P exhibited sustained levels. Mycobacterium spp. and Pseudomonas spp. gene copies rose significantly in PVC-P and PE-100 over time, indicating long-term enrichment. Aeromonas spp. were not detected in biofilms, remaining low in water throughout. Fungal gene copies fluctuated slightly, with increases observed only in PVC-P biofilm.
The study further revealed significant differences between water and biofilm phases. The ATP ratio (water/biofilm) indicated that materials like PVC-P and PE promoted biofilm dominance, whereas glass favored planktonic growth. This shift implies that certain materials enhance surface attachment and biomass accumulation, increasing the risk of pathogen persistence. Overall, the findings demonstrate that microbial dynamics are governed by both material properties and temporal evolution, with community stabilization occurring by week 8. These insights support the use of shorter incubation periods in future testing protocols while emphasizing the need for material-specific assessments in designing safe, biologically stable drinking water systems.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
