微酸性电解水对肠炎沙门氏菌的杀菌机制初探

A Preliminary on the Bactericidal Mechanism of Slightly Acidic Electrolyzed Water on Salmonella enteritidis

为研究微酸性电解水(Slightly Acidic Electrolyzed Water,SAEW)对肠炎沙门氏菌的杀菌机制,本文探讨了SAEW对肠炎沙门氏菌细胞膜通透性、细胞膜完整性、胞内活性氧(Reactive Oxygen Species,ROS)及胞内ATP等的影响。试验结果显示,有效氯浓度为10 mg/L的SAEW处理1 min后,可杀灭鸡蛋表面肠炎沙门氏菌2.04 lg(CFU/g);与对照组相比,SAEW处理组菌悬液的电导率升高,由13.78±0.13 ms/cm显著增加到16.32±0.10 ms/cm(P<0.05),蛋白质泄漏量增加,由0.07±0.04 g prot/L显著增长至0.30±0.03 g prot/L(P<0.05),核酸泄漏量增加,ROS积累量增加,胞内ATP含量降低。扫描电镜(Scanning Electron Microscope,SEM)显示,经SAEW处理后,肠炎沙门氏菌的细胞壁结构不完整,遭到破坏,有明显的穿孔现象,且许多细菌表面凹陷变形或破碎粘连。试验结果表明,SAEW能够显著提高肠炎沙门氏菌细胞膜的通透性并严重破坏细胞膜的完整性,导致细胞内蛋白质、核酸、ATP等内容物泄漏,进而导致肠炎沙门氏菌胞内ROS的积累。

In order to study the bactericidal mechanism of slightly acidic electrolyzed water(SAEW)against Salmonella enteritidis,the effects of SAEW on cell membrane permeability,cell membrane integrity,reactive oxygen species(ROS),and intracellular ATP of Salmonella enteritidis were studied.The results showed that 2.04 lg(CFU/g)of Salmonella enteritidis on the surface of eggshells was inactivated after the SAEW treatment at the available chlorine concentration of 10 mg/L for 1 min.Moreover,relative to the control group,the conductivity of bacterial suspension of Salmonella enteritidis was increased from 13.78±0.13 ms/cm to 16.32±0.10 ms/cm(P<0.05)in the SAEW group.In addition,the protein leakage in the bacterial cells was significantly increased from 0.07±0.04 g prot/L to 0.30±0.03 g prot/L(P<0.05).Moreover,the SAEW treatment increased the nucleic acid leakage and ROS accumulation and the intracellular ATP content reduction.The result of SEM also showed that,after the SAEW treatment,the cell wall structure of Salmonella enteritidis was incomplete,damaged and obviously perforated,and many bacterial surfaces were sunken,deformed or broken and adhered.The results showed that SAEW significantly increased the permeability and seriously destroyed the integrity of the cell membranes of Salmonella enteritidis,which led to the leakage of intracellular proteins,nucleic acids,ATP and other contents,leading to the accumulation of ROS.