Department of Chemical and Environmental Engineering, University of Toledo , Toledo, Ohio 43607, United States.
Environ Sci Technol. 2016 Sep 6;50(17):9197-205. doi: 10.1021/acs.est.6b00927. Epub 2016 Aug 10.
In our previous study, we reported that the transport of monochloramine is affected by the extracellular polymeric substance (EPS) composition, which in turn affects the cell viability of both biofilm and detached clusters.11 However, although the transport and reaction of monochloramine in biofilm could be observed, the specific biomolecules reacting with the disinfectant and the mechanism of disinfection remains elusive. In this study, the impact of EPS composition on bacteria disinfection by monochloramine was qualitatively determined using both wild-type and isogenic mutant Pseudomonas strains with different EPS-secretion capacity and composition. To evaluate their EPS reactivity and contribution to susceptibility to monochloramine, we investigated the bacteria disinfection process using Fourier transform infrared spectroscopy (FTIR) and matrix-assisted laser desorption-ionization time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF-MS). Canonical correlation analysis and partial least-squares regression modeling were employed to explore the changes that EPS underwent during the monochloramine disinfection process. The analyses results suggested significant reactions of the monochloramine with peptide fragments of proteins that are associated with carbohydrate utilization. Selected enzymes also showed different levels of inhibition by monochloramine when tested.
在我们之前的研究中，我们报告了一氯胺的传输受到细胞外聚合物质（EPS）组成的影响，而 EPS 组成又会影响生物膜和游离菌团的细胞活力。11 然而，尽管可以观察到生物膜中一氯胺的传输和反应，但与消毒剂反应的特定生物分子以及消毒机制仍不清楚。在这项研究中，使用 EPS 分泌能力和组成不同的野生型和同基因突变假单胞菌菌株，定性确定了 EPS 组成对一氯胺杀菌的影响。为了评估它们的 EPS 反应性及其对一氯胺敏感性的贡献，我们使用傅里叶变换红外光谱（FTIR）和基质辅助激光解吸电离飞行时间/飞行时间质谱（MALDI-TOF/TOF-MS）研究了细菌的消毒过程。典型相关分析和偏最小二乘回归建模被用来探索 EPS 在一氯胺消毒过程中的变化。分析结果表明，一氯胺与与碳水化合物利用相关的蛋白质肽片段发生了显著反应。当进行测试时，选定的酶对一氯胺的抑制作用也显示出不同的水平。
