The Role of Extracellular Polymeri Substances of Biofilm on Pathogen Disinfection in Water Distribution Systems

固定化微生物细胞生长并产生胞外聚合物(EPS)，产生有结构的微生物群落。固定化细胞和EPS一起形成生物膜。美国许多自来水公司的报告显示，尽管消毒剂持续存在，但生物膜仍在供水系统中存活，并对公众造成重大健康威胁。目前，生物膜在给水系统中的持久性被认为与EPS有很强的相关性。这项建议的主要目的是了解生物膜在供水系统中持续存在的机制。重点是了解生物膜EPS的作用，使用微电极技术和用于原位生物膜监测的荧光标记探针。提出的微电极技术和生物膜分析工具的研究将拓宽我们对病原菌生物膜形成及其消毒剂控制的理解。具体地说，这项研究将能够定量评估EPS和生物膜结构在消毒剂运输和反应中的作用。这将导致开发利用微电极和生物膜分析获得的建模参数。此外，我们还将确定EPS在病原体附着、脱离和再分布中的作用。最后，这项研究将对多种分布参数(水龄、活性管材、磷缓蚀剂)对多物种生物膜生长的影响进行联合评估。这项研究有新的关键方法，可以区别于以往的研究。首先，将用新开发的微电极和原位生物膜分析来确定二次消毒剂在生物膜中的未回答的迁移和反应动力学。其次，将使用系统的方法来观察EPS在生物膜脱离和再分布中的作用，监测分离的团簇的生理状态，这是粒度分析仪无法理解的。除了扩大学术界对生物膜控制的理解外，这项拟议的研究还对水务、工业和公众健康产生了直接和广泛的影响。这项研究收集到的信息将使当地的自来水公司能够纳入生物膜控制策略，并加深我们目前对包括医疗和化工行业在内的许多其他行业的生物膜控制机制的了解。这些成果将有助于通过改善通过饮用水预防与生物膜相关的病原体感染来保护公众健康，并提供对EPS对抗抗菌剂的作用的基本了解。此外，拟议的项目将为两名博士生提供培训和教育，为本科生和高中生提供暑期研究机会，并将研究成果落实到PIS的三个本科课程中。

0933288SeoImmobilized microbial cells grow and produce extracelluar polymeric substance (EPS), which create structured communities of microorganisms. Together, immobilized cells and EPS form a biofilm. Reports from many water utilities in the US have shown that biofilm survives in water distribution systems despite the continuing presence of disinfectants and causes significant health threats to the public. Currently, the persistence of biofilm in water distribution systems is believed to be strongly related to EPS. The principal objective of this proposal is to understand the mechanisms of the persistence of biofilm in water distribution systems. Emphasis will be placed on understanding the role of biofilm EPS, using microelectrodes techniques and fluorescently labeled probes for in-situ biofilm monitoring. The proposed studies with microelectrodes techniques and biofilm analysis tools will broaden our understanding of pathogenic biofilm formation and its control with disinfectants. Specifically, this research will enable quantitative evaluation of the role of EPS and biofilm structure on the transport and reaction of disinfectants. This will result in the development of modeling parameters obtained with microelectrodes and biofilm analysis. In addition, we will identify the role of EPS on pathogen attachment, detachment and redistribution. Finally, this research will result in combined assessments of the effects of multiple distribution parameters (water age, reactive pipe material, phosphorous corrosion inhibitor) on multi-species biofilm growth. This research has new key approaches which can be differentiated from previous studies. First, the unanswered transport and reaction kinetics of secondary disinfectants in biofilm will be determined with newly developed microelectrodes and in-situ biofilm analysis. Second, a systematic approach will be used to observe the role of EPS on the detachment and redistribution of biofilm, monitoring physiological states of detached clusters which couldn't be understood with particle size analyzers. Beyond enlarging our understanding of biofilm control in academic society, the proposed research has direct and broad impacts on water utilities, industries, and public health. The information gleaned from this research will enable local water utilities to incorporate biofilm control strategies and enhance our current understanding of biofilm control mechanism in many other industries including medical and chemical industries. The outcomes will contribute to protecting public health by improving the prevention of biofilm related pathogen infection via drinking water and providing a fundamental understanding of the role of EPS against antimicrobial agents. In addition, the proposed project will result in the training and education of two Ph.D students, summer research opportunities for undergraduate and high school students, and implementation of research findings into PIs three undergraduate courses.