| Summary: | 碩士 === 國立臺灣海洋大學 === 食品科學系 === 101 === Vibrio vulnificus is a Gram-negative bacteria, which lives in marine environment. V. vulnificus can cause rapidly progressing severe skin lesions and septicemia in humans, particularly those with chronic hepatic disorders. Acidic electrolyzed water (AEW) is a new sanitizer in recent years. AEW has been reported with strong bactericidal activity against many foodborne pathogens. To evaluate bactericidal activities of AEW against V. vulnificus, the bactericidal activity and effect of V. vulnificus were discussed after treated with AEW. AEW, NaOCl and phosphate buffered saline (PBS) have no significant change on pH, oxidation reduction potential (ORP) and available chlorine concentration (ACC) after the storage of 120 min at 25oC. For the effect of storage temperature on pH, ORP and ACC of AEW, ACC had significant change and the bactericidal activity was reduced. It was found that AEW could completely kill V. vulnificus when the AEW concentration was 50% for 30 sec. As the AEW concentration decreasing, the bactericidal activity gradually decreased. In addition, ACC of AEW has a significant effect on bactericidal activities against V. vulnificus. But pH and ORP did not show significant effect. Once V. vulnificus was treated with AEW and re-cultured, it was found that its growth rate with AEW treatment were slower, especially 10% AEW could not reach the original maximum amount of bacteria. Analyzing of the hemolytic activity with increased AEW concentration, the hemolytic activity of V. vulnificus decresed, the EC50 of control group was 10.48 mg / ml, and 10% AEW group was 26.66 mg / ml. Above all, AEW can be used as a bactericide against V. vulnificus, which had a significant bactericidal effect. If V. vulnificus was not dead completely, AEW also can make V. vulnificus grow slower and decrease its hemolytic activity. When comparing to the level of PBS group, and the sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS - PAGE) patterns of AEW group were changed indeed. The protein band numbers of SDS-PAGE were decreased in the testing solution treated groups, and this indicated that testing solution may destroy the proteins of V. vulnificus. NaOCl destroyed the proteins of V. vulnificus stronger than AEW and PBS. The two-dimensional electrophoresis (2DE) revealed that proteins were up-regulated or down-regulated after treated with AEW and NaOCl. The P1 protein may be outer membraned protein U related with osmotics pressure regulation.
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