McFeters G A, Broadaway S C, Pyle B H, Egozy Y
Department of Microbiology, Montana State University, Bozeman 59717.
Appl Environ Microbiol. 1993 May;59(5):1410-5. doi: 10.1128/aem.59.5.1410-1415.1993.
Experiments were conducted to measure communities of bacteria within operating ultrapure water treatment systems intended for laboratory use. Samples from various locations within Milli-Q Plus and Milli-Q UV Plus systems were analyzed for populations of planktonic bacteria at weekly intervals over 3 months of operation. Relatively high initial densities of planktonic bacteria (10(2) to 10(3) bacteria per ml) were seen within both units when they were challenged with source water of poor quality, although the product water continued to be acceptable with regard to bacterial numbers, resistivity, and endotoxin concentration. Under more normal operating conditions, significant differences were seen in planktonic populations throughout the systems with excellent product water quality. A great deal of variability was observed in biofilm populations analyzed from various system surfaces after 3 months of operation. The concentrations of planktonic bacteria and biofilm densities were much lower in the unit containing a UV lamp. These findings suggest that a range of microenvironmental conditions exist within purified water systems, leading to variable populations of bacteria. However, product water of excellent quality was obtained despite the bacterial communities.
开展了实验，以测量实验室用超纯水制备系统运行过程中的细菌群落。在Milli-Q Plus和Milli-Q UV Plus系统运行的3个月期间，每周对各个系统不同位置的样本进行分析，以测定浮游细菌数量。当两个系统采用劣质源水时，初始浮游细菌密度相对较高（每毫升10²至10³个细菌），不过产出水在细菌数量、电阻率和内毒素浓度方面仍可接受。在更正常的运行条件下，整个系统的浮游细菌数量存在显著差异，产出水质量极佳。运行3个月后，对各系统表面分析的生物膜数量观察到很大的变异性。装有紫外线灯的系统中浮游细菌浓度和生物膜密度要低得多。这些发现表明，纯化水系统中存在一系列微环境条件，导致细菌数量各异。然而，尽管存在细菌群落，但仍获得了质量极佳的产出水。
