基于PTS系统介导Z环错位的植物乳杆菌素Q7抑制荧光假单胞菌生长机理研究

植物乳杆菌素具有安全、广谱和高效的抑菌特性，是食品生物防腐剂的研究热点。细菌PTS系统被视为细菌素重要作用靶点，能介导Z环错位，导致细菌生长受阻。申请人前期获得了植物乳杆菌素Q7，可有效抑制食品中典型耐冷腐败菌荧光假单胞菌的生长。然而，基于糖PTS系统介导Z环错位的植物乳杆菌素抑制荧光假单胞菌生长的分子机制尚不清楚。本项目在前期工作基础上，以植物乳杆菌素Q7为研究对象，荧光假单胞菌为指示菌，采用糖代谢组学和Real-time PCR技术，锚定植物乳杆菌素抑制荧光假单胞菌的靶向糖PTS系统关键基因；利用分子生物学手段，构建靶向糖PTS系统关键基因缺失、回补及高表达菌株，对经植物乳杆菌素Q7处理后的荧光假单胞菌的Z环定位、组装及调控蛋白进行研究，揭示基于PTS系统介导Z环错位的植物乳杆菌素抑制荧光假单胞菌生长机制。本项目旨在为植物乳杆菌素预防和控制耐冷菌导致的食品腐败提供理论依据。

Plantaricin has attracted much attention because of safety, wide anti-microbial spectrum and high efficiency. PTS system from bacteria is an important target for antibacterial mechanism of bacteriocin. It can cause bacterial death by Z-ring dislocation. Plantaricin Q7 from the previous research has a good anti-Pseudomonas fluorescens activity, which is a typical food spoilage bacteria. At present, anti-Pseudomonas fluorescens molecular mechanism of plantaricin based on sugar PTS system is still unclear. On the basis of previous work, anti-Pseudomonas fluorescens key target sugar PTS system gene of plantaricin Q7 is determined by metabolomics and Real-time PCR analysis. Then, sugar PTS system knockout, compensation and overexpression strains are constructed by molecular biological techniques. After treatment with plantaricin Q7, Z-ring positioning, assembly and regulatory protein expression are researched. At last, antibacterial mechanism of plantaricin Q7 against Pseudomonas fluorescens by Z-ring based on PTS system are elucidated. The project aims to achieve better antimicrobial effect and provide a theoretical basis for preventing food spoilage caused by psychrotolerant bacterium.