超临界CO_(2)与姜精油协同对副溶血弧菌杀菌效果的影响与机制研究

Effects of Supercritical CO_(2) Combined with Ginger Essential Oil on the Sterilization of Vibrio parahaemolyticus and Its Mechanism

优化超临界CO_(2)低压、低温杀菌技术,降低细菌群体感应对杀菌效果的影响。采用液质联用法和苯酚硫酸法分别测定副溶血弧菌群体感应信号分子和胞外多糖的含量,采用微量扩散法测定所选群体感应抑制剂姜精油的群体感应抑制活性,优化联合超临界CO_(2)杀菌工艺。随着菌落总数的增加,群体感应信号分子和胞外多糖在菌悬液中积累,激活相关基因的表达从而增强菌体感应导致超临界CO_(2)杀菌效果下降。姜精油可作为群体感应抑制剂,其最小抑制浓度为200μg/mL,且在亚抑菌浓度下可以显著抑制副溶血弧菌的泳动性、生物膜形成(抑制率为64.20%)及菌悬液中的胞外多糖产生(抑制率为45.1%)。联合杀菌的最优工艺为群体感应抑制剂浓度75μg/mL,杀菌条件为15 MPa、40℃、20 min。姜精油可作为群体感应抑制剂应用于超临界CO_(2)杀菌可以大幅度提升其杀菌效果,为群体感应抑制剂的应用提供理论基础。

The objective is to optimize the low pressure and low temperature sterilization technology of supercritical CO_(2) and to reduce the influence of bacterial quorum sensing on the sterilization effect.The LC-MS and phenol sulfuric acid were used to determine the contents of quorum sensing signal molecules and exopolysaccharides of Vibrio parahaemolyticus,respectively.The micro diffusion method was applied to determine the quorum sensing inhibitory activity of selected quorum sensing inhibitor ginger essential oil,and the combined supercritical CO_(2) sterilization process was optimized.The quorum sensing signal molecules and exopolysaccharides accumulated in the bacterial suspension with the increase of the total number of colonies,activating the expression of related genes,thereby enhancing cell sensing,leading to the decline of the bactericidal effect of supercritical CO_(2).Ginger essential oil can be used as quorum sensing inhibitor,and the minimum inhibitory concentration was 200μg/mL,and it significantly inhibited the mobility of Vibrio parahaemolyticus,biofilm formation(64.20%of inhibition rate)and the production of exopolysaccharides in bacterial suspension(45.1%of inhibition rate)at the sub inhibitory concentration.The optimal process of quorum sensing inhibitor combined with supercritical CO_(2) sterilization is quorum sensing inhibitor concentration 75μg/mL,and the sterilization conditions are 15 MPa,40℃,and 20 min.In conclusion,ginger essential oil can be used as a quorum sensing inhibitor to enhance the effect of supercritical CO_(2) sterilization,providing a theoretical basis for the application of quorum sensing inhibitors.