Influence of Materials, Water Qualities and Disinfection Methods on the Drinking Water Biofilm Community

摘要

The composition of biofilm populations in drinking water will mainly depend on the nutrient availabilitynand the temperature. The nutrients may originate either from the raw water or from the installation materials. Tondetermine the effect of drinking water pipe materials on the composition of biofilm populations, biofilms grown onndifferent materials (EPDM materials, PEXb, PEXc and copper) were analyzed by cloning (16S rDNA) and thencommunity fingerprinting method denaturing gradient gel electrophoresis (DGGE). Additionally the long-term effect ofnmechanical cleaning and disinfection with chlorine dioxide (0.2 mg/l, 24h) on the biofilm populations was tested. Thenbiofilm populations had high diversities on growth supporting materials like EPDM and comparatively low diversity onnPEX. The biofilms were dominated by Proteobacteria and the composition of the subdivisions was influenced by thenapplied material. Flavobacteria and members of the family Sphingomonadaceae, which are known to degrade severalnorganic compounds, were found on EPDM materials and might be suitable as indicators for hygienical relevantnmaterials. Comparison of biofilms previously treated with disinfectants with untreated ones by DGGE revealed anconsiderable population shift depending on the pipe material.