食源性病原菌混合菌种生物被膜的形成规律研究

Biofilm exists widely in food production environments and so greatly threatens food safety. In natural states, biofilm generally consists of different species, which is called mixed-species biofilm. Combined with sampling of real production environment, this project focuses on the mixed-species biofilm which is formed by common and major foodborne pathogens. In this project, the formation ability of mixed-species biofilm and the type of interspecies interaction in it will be investigated by polystyrene microtiter plate method; the formation mechanism of mixed-species biofilm will be explored according to microbial quorum sensing, motility, extracellular polymeric substance and so on; the three-dimensional spatial structure of mixed-species biofilm will be unveiled by Cryo-scanning electron microscopy; the thickness, stiffness, an elastic constant and other physical parameters of mixed-species biofilm will be obtained by atomic force microscopy; and the metabolic changes of microbe in mixed-species biofilm will be studied through a metabolomic approach based on nuclear magnetic resonance spectroscopy and gas chromatography-mass spectrometry. Thus, the regular pattern of mixed-species biofilm formation by foodborne pathogens will be clarified. Also in this project, the mixed-species biofilm will be treated by the low temperature atmospheric pressure air plasma, and the inactivation and removal mechanism can be studied to support theory basis for the efficient control method on mixed-species biofilms. The results of this project can provide some valuable theoretical guidance for assessing the risk of biofilm contamination in food-producing environment and working out the efficient scheme to eradicate biofilm.

生物被膜在食品生产环境中广泛存在，给食品安全带来极大威胁。在自然状态下，生物被膜通常是由不同菌种形成的混合菌种生物被膜。本项目结合实际生产取样，以常见的食源性病原菌形成的混合菌种生物被膜为研究对象，利用聚苯乙烯微效价板法考察混合菌种生物被膜的形成能力及其中的种间相互作用类型；从微生物的群体感应、群游力和胞外多聚物等诸多方面探索混合菌种生物被膜的形成机制；通过冷冻扫描电镜和原子力显微镜观察分析揭示混合菌种生物被膜的三维空间结构及厚度、弹性常数、硬度等物理参数；使用基于核磁共振、气质联用技术的代谢组学研究方法，研究微生物在混合菌种生物被膜中的代谢变化，阐明食源性病原菌混合菌种生物被膜的形成规律；同时拟研究常压低温空气等离子体对混合菌种生物被膜的杀灭及去除效果及机理。本项目研究成果能够为评估食品生产环境中的生物被膜污染风险、制定高效的生物被膜的清除方案提供理论指导。

本项目以常见的食源性病原菌形成的混合菌种生物被膜为研究对象，利用聚苯乙烯微效价板法考察混合菌种生物被膜的形成能力及其中的种间相互作用类型；从细菌的群体感应、群游力和胞外多聚物等诸多方面探索混合菌种生物被膜的形成机制；通过冷冻扫描电镜观察揭示混合菌种生物被膜的三维空间结构；使用基于LC-MS/MS测技术的代谢组学研究方法，研究细菌在混合菌种生物被膜中的代谢变化。我们还考察了常温常压等离子体对生物被膜中致病菌的杀灭作用。为评估食品生产环境中的生物被膜污染风险、制定高效的生物被膜的清除方案提供理论指导。