ε-聚赖氨酸盐酸盐对鼠伤寒沙门氏菌的抑制效果及其在湿米粉中的应用

Inhibition of Salmonella typhimurium Growth byε-Poly-Lysine Hydrochloride and Its Consequent Use in Wet Rice Noodles

为了研究ε-聚赖氨酸盐酸盐(ε-Poly-Lysine hydrochloride,ε-PLH)对鼠伤寒沙门氏菌(Salmonella typhimurium,S.typhimurium)的抑菌作用,测定最小抑菌浓度(Minimum Inhibitory Concentration,MIC)和绘制生长曲线评估ε-PLH对S.typhimurium的抑菌效果。通过碘化丙啶渗透和胞内大分子泄露实验探究ε-PLH对S.typhimurium细胞膜的作用,并测定胞内活性氧(Reactive Oxygen Species,ROS)和超氧化物歧化酶(Superoxide Dismutase,SOD)活性以及ATP酶活性和ATP含量,探究ε-PLH对S.typhimurium氧化应激和能量代谢的影响。研究发现:ε-PLH对S.typhimurium有良好抑菌性,MIC为128μg/mL,能够有效抑制S.typhimurium的生长,经MICε-PLH处理后的S.typhimurium细胞膜完整性被破坏,细胞膜渗透性改变,活性氧过量积累,处理6 h后核酸泄露量和ROS水平分别为对照组的2.45倍和1.99倍,SOD和ATP酶活性以及ATP含量分别比对照组下降29.60%、10.00%和67.63%。ε-PLH作用于细胞膜,造成S.typhimurium氧化损伤,破坏细菌胞内能量平衡,进而影响其正常生命活动导致死亡。此外,将ε-PLH应用于湿米粉,发现ε-PLH对S.typhimurium仍有一定抑菌效果,并且具有良好保鲜效果。综上,ε-PLH具有控制食品中沙门氏菌污染的潜力。

Here,to investigate the inhibitory effect ofε-poly-lysine hydrochloride(ε-PLH)on the growth of Salmonella typhimurium,the minimum inhibitory concentration(MIC)was determined and the growth curve was plotted.The effect ofε-PLH on the cell membrane of S.typhimurium was investigated by evaluating propidium iodide(PI)infiltration and intracellular macromolecule leakage.The effects ofε-PLH on oxidative stress and energy metabolism in S.typhimurium were explored by measuring the intracellular reactive oxygen species(ROS)levels,superoxide dismutase(SOD)and ATPase activities,and ATP content.The results revealed thatε-PLH exhibits robust antibacterial properties in the context of S.typhimurium,with an MIC of 128μg/mL.Further,ε-PLH was found to effectively inhibit the growth of S.typhimurium.Following treatment withε-PLH at the MIC,the integrity of the S.typhimurium cell membrane was lost,leading to changes in cell membrane permeability and excessive accumulation of ROS.After 6 h of treatment,the levels of nucleic acid leakage and ROS were 2.45 and 1.99 times higher than those in the control group.Further,compared to the control group,the SOD activity,ATPase activity,and ATP content decreased by 29.60,10.00,and 67.63%,respectively,in theε-PLH-treated group.ε-PLH treatment affected the cell membrane of S.typhimurium;this caused oxidative damage and disruption of the intracellular energy balance,ultimately leading to impaired physiological functions and death in S.typhimurium.Furthermore,treatment of wet rice noodles withε-PLH revealed thatε-PLH still exhibited an antibacterial effect against S.typhimurium and had a good fresh-keeping effect.In conclusion,ε-PLH exhibits promising potential with respect to the control of Salmonella contamination in food.