Abstract：
Extracellular polymeric substances (EPS) ubiquitously encapsulate microbes and play crucial roles in various environmental processes. However, understanding their complex interactions with dynamic bacterial behaviors, especially during the disinfection process, remains very limited. In this work, we investigated the impact of EPS on bacterial disinfection kinetics by developing a permanent EPS removal strategy. We genetically disrupted the synthesis of exopolysaccharides, the structural components of EPS, in Pseudomonas aeruginosa, a well-known EPS-producing opportunistic pathogen found in diverse environments, creating an EPS-deficient strain. This method ensured a lasting absence of EPS while maintaining bacterial integrity and viability, allowing for real-time in situ investigations of the roles of EPS in disinfection. Our findings indicate that removing EPS from bacteria substantially lowered their susceptibility threshold to disinfectants such as ozone, chloramine B, and free chlorine. This removal also substantially accelerated disinfection kinetics, shortened the resistance time, and increased disinfection efficiency, thereby enhancing the overall bactericidal effect. The absence of EPS was found to enhance bacterial motility and increase bacterial cell vulnerability to disinfectants, resulting in greater membrane damage and intensified reactive oxygen species (ROS) production upon exposure to disinfectants. These insights highlight the central role of EPS in bacterial defenses and offer promising implications for developing more effective disinfection strategies.
摘要：
细胞外聚合物（EPS）无处不在地包裹微生物，并在各种环境过程中发挥关键作用。然而,了解它们与动态细菌行为的复杂相互作用，特别是在消毒过程中，仍然非常有限。在这项工作中,通过开发永久性EPS去除策略,研究了EPS对细菌消毒动力学的影响.我们从基因上破坏了胞外多糖的合成，EPS的结构部件，在铜绿假单胞菌中，一种在不同环境中发现的众所周知的产生EPS的机会病原体，创造一个缺乏EPS的菌株。这种方法确保了EPS的持久缺失，同时保持了细菌的完整性和活力。允许实时现场调查EPS在消毒中的作用。我们的发现表明，从细菌中去除EPS大大降低了它们对臭氧等消毒剂的敏感性阈值，氯胺B,和游离氯。这种去除也大大加速了消毒动力学，缩短了电阻时间，提高了消毒效率，从而增强整体杀菌效果。发现不存在EPS会增强细菌运动性并增加细菌细胞对消毒剂的脆弱性，暴露于消毒剂后，会导致更大的膜损伤和活性氧（ROS）的产生。这些见解强调了EPS在细菌防御中的核心作用，并为开发更有效的消毒策略提供了有希望的意义。
