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

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.