脂环酸芽孢杆菌是苹果汁生产中的关键质量安全指标之一。乳酸菌细菌素安全稳定、抗菌活性强，为脂环酸芽孢杆菌控制提供一条新途径。申请人前期研究获得Class IIa类乳酸菌细菌素plantaricin YKX，对脂环酸芽孢杆菌具有良好抗菌活性，且在亚抑菌浓度下能够影响脂环酸芽孢杆菌的群体感应（QS）系统，但具体调控机理尚不清楚。本项目在此基础上，通过研究：①亚抑菌浓度plantaricin YKX对脂环酸芽孢杆菌QS相关群体行为的影响；②对QS信号分子及其合成蛋白的影响；③对QS系统相关生物学通路的影响，拟成功揭示plantaricin YKX在亚抑菌浓度下对脂环酸芽孢杆菌QS系统的调控机理，为将其应用于苹果汁中脂环酸芽孢杆菌污染控制提供理论基础。为实现上述目标，本项目综合运用了激光共聚焦显微镜、SDS-PAGE凝胶电泳、圆二色光谱、LC-MS、拉曼光谱、分子对接、转录/蛋白质组学等技术手段。

Alicyclobacillus.spp is one of the most important evaluation indexes regarding to the food quality and food safety during the production of Apple Juice. Bacteriocins have stable characterization and strong antibacterial activity so they’d better be considered as a new way for the control of Alicyclobacillus.spp. In preliminary study, the applicant obtained a class IIa bacteriocin, named as plantaricin YKX, which has good antibacterial activity against Alicyclobacillus.spp and is able to affect the quorum sensing (QS) system of Alicyclobacillus.spp. However, the specific regulatory mechanism is still not clear yet. In such a case, the applicant plan to do the study focused on ① influence of plantaricin YKX on Alicyclobacillus.spp QS regarding bio-behaviors at sub MICs; ②the effect of plantaricin YKX plantaricin YKX on the QS signal molecules and their synthesis protein; ③the influence of plantaricin YKX on the QS system regarding biological pathways. The aim of the research is to reveal the Regulatory Mechanism of Class IIa Bacteriocins Plantaricin YKX on the QS system of Alicyclobacillus.spp at sub MICs and provide the fundamental data for the application of plantaricin YKX on the control of Alicyclobacillus.spp in apple juice industry. To fulfil this goal, the applicant used the technology of laser confocal microscopy, SDS-PAGE electrophoresis, circular dichroism spectroscopy, LC-MS, Raman spectroscopy, molecular docking, transcriptional / proteomic techniques all together.