Wingender J, Flemming H C
Institute for Interface Biotechnology, Department of Aquatic Microbiology, University of Duisburg-Essen, Geibelstrasse, Duisburg, Germany.
Water Sci Technol. 2004;49(11-12):277-86.
Drinking water distribution system biofilms were investigated for the presence of hygienically relevant microorganisms. Early biofilm formation was evaluated in biofilm reactors on stainless steel, copper, polyvinyl chloride (PVC) and polyethylene coupons exposed to unchlorinated drinking water. After 12 to 18 months, a plateau phase of biofilm development was reached. Surface colonization on the materials ranged between 4 x 10(6) and 3 x 10(7) cells/cm2, with heterotrophic plate count (HPC) bacteria between 9 x 10(3) and 7 x 10(5) colony-forming units (cfu)/cm2. Established biofilms were investigated in 18 pipe sections (2 to 99 years old) cut out from distribution pipelines. Materials included cast iron, galvanized steel, cement and PVC. Colonization ranged from 4 x 10(5) to 2 x 10(8) cells/cm2, HPC levels varied between 1 and 2 x 10(5) cfu/cm2. No correlation was found between extent of colonization and age of the pipes. Using cultural detection methods, coliform bacteria were rarely found, while Escherichia coli, Pseudomonas aeruginosa and Legionella spp. were not detected in the biofilms. In regular operation, distribution system biofilms do not seem to be common habitats for pathogens. However, nutrient-leaching materials like rubber-coated valves were observed with massive biofilms which harboured coliform bacteria contaminating drinking water.
对饮用水分配系统生物膜进行了研究，以检测是否存在与卫生相关的微生物。在生物膜反应器中，对暴露于未氯化饮用水的不锈钢、铜、聚氯乙烯（PVC）和聚乙烯试片上的早期生物膜形成情况进行了评估。12至18个月后，生物膜发育进入平稳期。材料表面的菌落数在4×10⁶至3×10⁷个细胞/平方厘米之间，其中异养平板计数（HPC）细菌在9×10³至7×10⁵个菌落形成单位（cfu）/平方厘米之间。从配水管道中截取了18个管段（使用年限为2至99年），对已形成的生物膜进行了研究。材料包括铸铁、镀锌钢、水泥和PVC。菌落数在4×10⁵至2×10⁸个细胞/平方厘米之间，HPC水平在1至2×10⁵个cfu/平方厘米之间。未发现菌落数与管道使用年限之间存在相关性。采用培养检测方法，很少发现大肠菌群，而在生物膜中未检测到大肠杆菌、铜绿假单胞菌和军团菌属。在正常运行中，分配系统生物膜似乎不是病原体的常见栖息地。然而，观察到像橡胶涂层阀门这样的营养浸出材料上有大量生物膜，其中含有污染饮用水的大肠菌群。
