Jaeggi N E, Schmidt-Lorenz W
Laboratorium für Lebensmittel-Mikrobiologie, Eidg. Technische Hochschule (ETH) Zürich.
Zentralbl Bakteriol Mikrobiol Hyg B Umwelthyg Krankenhaushyg Arbeitshyg Prav Med. 1988 Jul;186(4):311-25.
Seven dead-end water pipes were installed after each treatment step in a drinking water plant. During a period of 7 weeks the bacterial load of freshwater and stagnating water was investigated with different methods. A modified surface spread plate count (Plate Count Agar, 10-fold diluted, 14 days incubation at 20 degrees C) proved to be more effective than the traditional pour plate method, because it gave consistently higher colony counts and had a lower level of detection (0.001 CFU ml-1). The enumerating of electron-transport-system positive bacteria yielded higher numbers than the colony count methods, but is not recommended when recently oxidized water samples are to be investigated. Highest cell counts were attained when using epifluorescence microscopic counting, yet bacterial regrowth could not be monitored thus. The tendency of bacterial regrowth was highest in freshly ozonized water. In stagnating lake water no regrowth occurred after 1 and 3 weeks because of the balance of bacteria and their predators.
在一家饮用水处理厂的每个处理步骤之后，安装了7根盲端水管。在7周的时间里，采用不同方法对淡水和滞水的细菌负荷进行了调查。改良的表面涂布平板计数法（平板计数琼脂培养基，10倍稀释，20℃培养14天）被证明比传统的倾注平板法更有效，因为它能持续给出更高的菌落计数，且检测限更低（0.001 CFU/ml）。电子传递系统阳性细菌的计数结果比菌落计数法得到的数字更高，但在调查最近被氧化的水样时不推荐使用。使用落射荧光显微镜计数可获得最高的细胞计数，但无法据此监测细菌的再生长情况。细菌再生长的趋势在刚经过臭氧处理的水中最高。在滞水湖泊水中，由于细菌与其捕食者之间的平衡，1周和3周后未出现再生长现象。
