Deposition and Survival of Escherichia coli O157:H7 on Clay Minerals in a Parallel Plate Flow System
Deposition and Survival of Escherichia coli O157:H7 on Clay Minerals in a Parallel Plate Flow System
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平行板流系统中粘土矿物上大肠杆菌 O157:H7 的沉积和存活
DOI：
10.1021/es304686a
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发表时间：
2013-02-19
影响因子：
11.4
通讯作者：
Walker, Sharon L.
中科院分区：
文献类型：
--
作者：
Cai, Peng;Huang, Qiaoyun;Walker, Sharon L.
了解细菌病原体在土壤地下水系统中的沉积和存活过程对于保护公众健康免受土传和水传疾病的影响至关重要。然而，细菌病原体粘土相互作用的机制还没有得到很好的研究，特别是在动态系统中。此外，人们对细菌病原体附着在粘土上的生存能力知之甚少。在这项研究中，平行板流动系统被用来确定的沉积动力学和生存的大肠杆菌O 157：H7蒙脱石，高岭石，针铁矿在很宽的范围内的离子强度（IS）（0.1-100 mM KO）。E. coliO 157：H7在带正电荷的针铁矿上的沉积量大于在带负电荷的高岭石和蒙脱石上的沉积量。虽然高岭石的zeta电位比蒙脱石负，但高岭石对E. coliO 157：H7比蒙脱石更易溶出，这是由于粘土矿物的化学不均一性造成的。总体而言，增加IS导致E增加。coliO 157：H7在蒙脱石和高岭石上沉积，在针铁矿上减少。相互作用能计算表明，E。大肠杆菌O 157：H7在粘土上的沉积主要受DLVO（Derjaguin-Landau-Verwey-Overbeek）力控制。使用Live/Dead BacLight活力测定法研究细菌膜完整性的损失作为时间的函数。在检测的6 h内，E. coli O 157：H7在悬浮液中以及附着在蒙脱石和高岭石上时保持其活力;然而，与针铁矿的相互作用是有害的。本研究所获得的信息对于了解细菌病原体在土壤环境中的命运具有重要意义。
Understanding bacterial pathogens deposition and survival processes in the soil groundwater system is crucial to protect public health from soilborne and waterborne diseases. However, mechanisms of bacterial pathogen clay interactions are not well studied, particularly in dynamic systems. Also, little is known about the viability of bacterial pathogens when attached to clays. In this study, a parallel plate flow system was used to determine the deposition kinetics and survival of Escherichia coli O157:H7 on montmorillonite, kaolinite, and goethite over a wide range of ionic strengths (IS) (0.1-100 mM KO). E. coli O157:H7 deposition on the positively charged goethite is greater than that on the negatively charged kaolinite and montmorillonite. Although the zeta potential of kaolinite was more negative than that of montmorillonite, kaolinite showed a greater deposition for E. coli O157:H7 than montmorillonite, which is attributed to the chemical heterogeneity of clay minerals. Overall, increasing IS resulted in an increase of E. coli O157:H7 deposition on montmorillonite and kaolinite, and a decrease on goethite. Interaction energy calculations suggest that E. coli O157:H7 deposition on clays was largely governed by DLVO (Derjaguin-Landau-Verwey-Overbeek) forces. The loss of bacterial membrane integrity was investigated as a function of time using the Live/Dead BacLight viability assay. During the examined period of 6 h, E. coli O157:H7 retained its viability in suspension and when attached to montmorillonite and kaolinite; however, interaction with the goethite was detrimental. The information obtained in this study is of fundamental significance for the understanding of the fate of bacterial pathogens in soil environments.