Shandong Province Water Supply and Drainage Monitoring Center, Jinan, 250000, China; College of Environmental Science and Engineering, Shandong Jianzhu University, Jinan, 250101, China.
Shandong Province Water Supply and Drainage Monitoring Center, Jinan, 250000, China.
Environ Res. 2020 Jun;185:109417. doi: 10.1016/j.envres.2020.109417. Epub 2020 Mar 21.
Lack of microbial contamination is crucial for drinking water quality and safety. Chlorine-resistant bacteria in drinking water distribution systems pose a threat to drinking water quality. A bacterium was isolated from an urban water supply network in northern China and identified as Pseudomonas peli by 16S rDNA gene analysis. This P. peli strain had high chlorine tolerance. The CT value (the product of disinfectant concentration and contact time) to achieve 3 lg unit (i.e. 99.9%)-inactivation of this P. peli isolate was 51.26-90.36 mg min/L, inversely proportional to the free chlorine concentration. Chlorine dioxide could inactivate the bacterium faster and more efficiently than free chlorine, as shown by flow cytometry. Thiazole orange plus propidium iodide staining indicated that free chlorine and chlorine dioxide inactivated P. peli primarily by disrupting the integrity and permeability of the cell membrane. The P. peli was also sensitive to ultraviolet (UV) radiation; a UV dose of 40 mJ/cm achieved 4 lg unit (99.99%)-inactivation. The Hom model was more suitable for analyzing the disinfection kinetics of P. peli than the Chick and Chick-Watson models.
缺乏微生物污染对于饮用水的质量和安全至关重要。饮用水分配系统中的耐氯细菌对饮用水水质构成威胁。从中国北方城市供水管网中分离到一株细菌，通过 16S rDNA 基因分析鉴定为假单胞菌属的 P. peli。该 P. peli 菌株具有较高的耐氯性。达到 3 lg 单位（即 99.9%）灭活所需的 CT 值（消毒剂浓度与接触时间的乘积）为 51.26-90.36 mg min/L，与游离氯浓度成反比。与游离氯相比，二氧化氯能更快、更有效地灭活该细菌，这一点通过流式细胞术得到了证实。噻唑橙加碘化丙啶染色表明，游离氯和二氧化氯主要通过破坏细胞膜的完整性和通透性来灭活 P. peli。P. peli 对紫外线（UV）辐射也很敏感；40 mJ/cm 的 UV 剂量可实现 4 lg 单位（99.99%）的灭活。与 Chick 和 Chick-Watson 模型相比，Hom 模型更适合分析 P. peli 的消毒动力学。
