Division of Environmental Engineering, Faculty of Engineering, Hokkaido University, North-13, West-8, Sapporo 060-8628, Japan E-mail:
Cellspect Co., Ltd, 1-10-82 Kitaiioka, Morioka, Iwate 020-0857, Japan.
Water Sci Technol. 2021 Mar;83(6):1399-1406. doi: 10.2166/wst.2021.072.
Monitoring of Escherichia coli concentrations in river water (RW) is essential to identify fecal pollution of the river. The objective of this study was to assess the suitability of a novel, simple and high throughput method developed in our laboratory to enumerate E. coli concentrations in RW samples. The method is based on the use of the synthetic substrate specific for the β-d-glucuronidase (GUS) produced by E. coli. GUS activities and E. coli concentrations were monitored at eight selected sites in rivers running through Sapporo, Japan. Because the fluorescence intensities of the synthetic substrate in the RW samples increased linearly over a 4-h incubation period, we could estimate the GUS activities of the RW samples. The GUS activities were highly correlated with E. coli concentrations at >100 most probable numbers 100 mL with a correlation coefficient of 0.87. The GUS activities of the RW samples collected from all sampling sites fitted well to a single correlation equation, which indicates that it was applicable to the estimation of E. coli concentrations regardless of the sampling sites. This method is simple, rapid, reliable, inexpensive, and high throughput, and is therefore useful for monitoring E. coli in RW.
监测河水中大肠杆菌的浓度对于识别河水受到粪便污染非常重要。本研究的目的是评估我们实验室开发的一种新颖、简单和高通量的方法，用于测定河流水样中的大肠杆菌浓度。该方法基于使用合成底物特异性检测大肠杆菌产生的β-d-葡萄糖醛酸酶（GUS）。在日本札幌市流经的 8 个选定地点监测了 GUS 活性和大肠杆菌浓度。由于在 4 小时孵育期间，RW 样品中合成底物的荧光强度呈线性增加，因此我们可以估计 RW 样品中的 GUS 活性。GUS 活性与 >100 个最可能数 100 mL 内的大肠杆菌浓度高度相关，相关系数为 0.87。从所有采样点采集的 RW 样品的 GUS 活性符合单个相关方程，这表明无论采样点如何，该方法都适用于大肠杆菌浓度的估计。该方法简单、快速、可靠、廉价且高通量，因此可用于监测 RW 中的大肠杆菌。
