有机磷农药在农业生产中广泛使用，在农产品中的残留给食品安全带来极大隐患。以往研究大多集中于环境中有机磷农药的生物降解，近年利用食源性微生物对有机磷农药的降解研究引起关注。乳酸菌在食品工业中有广泛的应用，多项研究发现其对有机磷农药具有降解作用。本项目组亦筛选出对有机磷农药具有降解促进作用的几十株乳酸菌菌株，并且确定了乳酸菌磷酸酯酶和有机磷农药降解之间的相关性。但酶的作用机理尚不明确，基于此，本申请课题拟采用层析技术提取纯化乳酸菌发酵体系中的磷酸酯酶，分析酶的化学和催化动力学特性；并将纯化后的酶直接作用于有机磷化合物，用气相色谱质谱联用技术分析有机磷农药的降解产物，根据其组成和结构分析降解途径；用分子对接方法模拟酶与农药的相互作用。重点研究有机磷农药在磷酸酯酶作用下的降解模式与途径，以揭示乳酸菌发酵体系的酶促降解农药作用机理，为实现开发高效降解有机磷农药的食品级菌株的筛选和应用提供基本依据。

Organophosphorus pesticides (OPPs) are a group of chemical pesticides widely used in agriculture presently. Pollution of agriculture products resulted from OPPs residues brings risks to the food safety. Most studies focused on their environmental microbial degradations, recently researches on biodegradation of OPPs via food borne microorganisms have been attacking attention. Lactic acid bacteria (LAB) are widely used in food industry. Recent researches revealed its ability to degrade OPPs. Dozens of strains of LAB with high degradation activity were screened by my team, and their potential relationship with the secreted phosphatase was confirmed, but possible mechanism remains unknown. For this purpose, the phosphatase from LAB in a fermentation system will be isolated and purified by chromatography in this study. The chemistry and catalytic kinetics properties will be analyzed. The purified phosphatase will be applied directly in the OPP degradation. The molecular docking method will be used to investigate the binding modes of OPP to phosphatase.The Composition and content of the decomposition products analyzed by GC-MS were used to reveal the major pathway and pattern of degradation. The research aims of this project are to provide the basis information for the application and screening of food borne microorganisms with high OPP degradation activity.