鱼源产气肠杆菌QS信号分子（AHLs）的产生条件及其介导鲭鱼组胺累积的调控机制

项目名称： 鱼源产气肠杆菌QS信号分子（AHLs）的产生条件及其介导鲭鱼组胺累积的调控机制

项目编号： No.31301421

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 农业科学

项目作者： 邹宇

作者单位： 大连民族学院

项目金额： 25万元

中文摘要： 本项目以源于鲭鱼的高产组胺生产菌-产气肠杆菌的群体感应（quorum sensing, QS）信号分子（N-acyl-homoserine lactones, AHLs）为研究对象，通过考察营养与环境因子和细菌生长阶段对AHLs浓度的影响，确定AHLs的产生条件；采用柱层析和高效液相色谱纯化并鉴定AHLs，探明AHLs的理化性质和影响稳定性的因素。在此基础上，测定鲭鱼贮藏过程中AHLs浓度、菌体密度、组氨酸脱羧酶（HDC）活力和鲭鱼组胺含量，确定产气肠杆菌QS与鲭鱼组胺累积的关系；同时分析QS启动阈值前后不同AHLs浓度下HDC基因的表达水平和相关酶蛋白的合成量，从分子水平上揭示产气肠杆菌QS信号分子介导鲭鱼贮藏期间组胺合成的调控机制。本研究将进一步阐明食源性微生物产生有毒物质的形成途径，其结果将为基于阻断QS信号分子传导为靶点的海洋生鲜食品贮藏保鲜和安全生产新技术的研发提供基础理论支持。

中文关键词： 信号分子；组氨酸脱羧酶；组胺；基因表达；调控机制

英文摘要： In this project, quorum sensing (QS) signal molecule N-acyl-homoserine lactones (AHLs) produced by Enterobacter aerogenes (E. aerogenes), a high histamine-producing bacterium isolated from Chub mackerel (C. mackerel), will be investigated. Effects of nutritional and environmental factors and growth phase of bacteria on AHLs contents will be studied to determine production conditions of AHLs. By column chromatography and HPLC, AHLs will be purified and identified, and its physicochemical properties and stabilities of various conditions will also be researched. On this basis, AHLs contents, cell densities, histidine decarboxylase (HDC) activities and C. mackerel histamine contents will be measured to determine the relationship between E. aerogenes QS and histamine accumulation of C. mackerel. At the same time, the effects of different AHLs contents changed around QS starting content on expression level of HDC gene and synthesis of enzyme protein will also be explored. Subsequently, the regulation mechanism of QS signal molecule from E. aerogenes on systhesis of histamine during C. mackerel storage are revealed on the molecular biological levels. This study will further illustrate the formation way of toxic substances produced by food-borne microorganism. Meanwhile, the experimental results will also provide basic

英文关键词： Signal molecule；Histidine decarboxylase；Histamine；Gene expression；Regulation mechanism