标准摘要
[中文适用范围]： ISO 9308 的这一部分描述了大肠杆菌 (E. coli) 和大肠菌群的计数方法。 该方法基于膜过滤、随后在显色大肠菌琼脂 (CCA) 上培养以及计算样品中目标生物体的数量。 由于琼脂对初级富集的选择性较低，伴随的菌群可能会干扰大肠杆菌和大肠菌群的可靠计数，例如大肠杆菌。 B. 地表水或近地表井中的水。 此方法不适用于此类水。 ISO 9308 的这一部分对于测试细菌计数低的水特别有用，在显色大肠菌琼脂 (CCA) 上生长的菌落总数少于 100 个。 这可以是饮用水、消毒的游泳池水或来自水处理厂的即用水。 一些 -D-葡萄糖醛酸酶阴性的大肠杆菌菌株，例如B. 大肠杆菌 O157，未鉴定为大肠杆菌。 因为它们是-D-半乳糖苷酶阳性，所以它们在显色琼脂上显示为大肠菌。 [外文原描述]： ISO 9308-1:2014 specifies a method for the enumeration of Escherichia coli ( E. coli ) and coliform bacteria. The method is based on membrane filtration, subsequent culture on a chromogenic coliform agar medium, and calculation of the number of target organisms in the sample. Due to the low selectivity of the differential agar medium, background growth can interfere with the reliable enumeration of E. coli and coliform bacteria, for example, in surface waters or shallow well waters. This method is not suitable for these types of water. ISO 9308-1:2014 is especially suitable for waters with low bacterial numbers that will cause less than 100 total colonies on chromogenic coliform agar (CCA). These may be drinking water, disinfected pool water, or finished water from drinking water treatment plants. Some strains of E. coli which are β-D-glucuronidase negative, such as Escherichia coli O157, will not be detected as E. coli . As they are β-D-galactosidase positive, they will appear as coliform bacteria on this chromogenic agar.
英文名称Water quality — Enumeration of Escherichia coli and coliform bacteria — Part 1: Membrane filtration method for waters with low bacterial background flora