食源假单胞菌群体感应信号分子的研究

Research on Quorum Sensing Signal Molecules of Pseudomonas spp.Isolated from Food

摘要:

从市售鲜鱼中分离的3株革兰氏阴性菌,经16S rDNA鉴定为假单胞菌属,该菌是一种导致食品腐败的重要腐败细菌。N-酰基-高丝氨酸内酯(AHLs)是革兰氏阴性菌群体感应(QS)系统中一类重要的信号分子,以密度依赖的方式调控某些生理性状的表达。利用AHLs检测菌株对3株假单胞菌进行检测发现,均产生AHLs类信号分子,且FML05-1和FML05-2至少产生两种AHLs,主要的信号分子是N-3-氧代-辛酰基-高丝氨酸内酯(N- 3-oxo-C₈-HSL)。同时对菌株FML05-2在生长过程中所产生的AHLs的活性变化进行研究,发现AHLs活性在菌体生长至12h时达到最大。首次对食源假单胞菌所产生的AHLs进行了研究,为以干扰腐败细菌群体感应为靶点的食品防腐保鲜策略提供研究基础。

Abstract:

Three Gram-negative bacteria from commercial fresh fish were identified as Pseudomonas sp.,an important food spoilage bacteria, on the basis of 16S rDNA sequences.N-aeyl-homoserine lactones (AHLs) were the important quorum sensing molecules and regulated the expression of many characteristics in a cell-density-dependent manner in Gram-negative bacteria.The AHL biosensor detection revealed that three isolates produced AHLs molecules and strains FML05-1 and FML05-2 produced two types of AHLs at least and the main signal mole-cules were N-3-oxo-octanoyl-homoserine lactone (N-3-oxo-C₈-AHL).Also the amount of AHL in FML05-2 reached to the maximun at 12h throughout growth.This was first study of quorum sensing signal molecule AHLs produced by the pseudomonas from food and layed the foun-dation for new strategies of food preservation based on interfering in quorum sensing of spoilage bacteria.