29F-19 |
Effect of environmental factors on the efficacy of Pleurocidin, an antimicrobial peptide isolated from the winter flounder |
O. J. BURROWES1, T. C. Lee1, and G. Diamond2. (1) Dept. of Food Science, Rutgers, The State Univ. of New Jersey, 65 Dudley Rd., New Brunswick, NJ 08901-8520, (2) Dept. of Cell Biology & Molecular Medicine, Univ. of Medicine & Dentistry of New Jersey, 185 South Heights, Medical Science Bldg., Rm. C-634, Newark, NJ 07103-2714 Cationic peptides are promising potential food preservatives due to their ability to destroy microorganisms by assuming amphipathic structures, interacting directly with the microbial cell membrane, rapidly disrupting the membrane in several locations, unlike traditional antimicrobial agents which target specific molecular sites. To date, nisin is the only natural antimicrobial peptide approved by the FDA for use as a food preservative, however nisin does not inhibit Gram negative bacteria or fungi and is only active at low pH. Pleurocidin, a natural cationic peptide isolated from the edible winter flounder had been shown to be active against a wide-range of foodborne microorganisms, retains activity after 5 minutes boiling and tolerant to 3.3% salt, without deleterious effect on human cells. Our objective was to investigate the effect of environmental factors on the efficacy of pleurocidin using the seafood pathogen Vibrio parahemolyticus as the test organism. The efficacy of pleurocidin against Vibrio parahemolyticus was tested by determination of Minimal Inhibitory Concentrations (MIC) using the micro titer plate method before and after being subjected to various heat treatments including autoclaving, pH range 4-8 and salt concentrations 2.5 – 10% (NaCl). Our results revealed that pleurocidin is effective over a wide pH range, retaining its activity at both basic and acidic pHs. Pleurocidin was also found to be heat tolerant, retaining full activity after autoclaving (1210C/15 mins/15psi) and also salt tolerant up to pH 7.5. These results are of significance to the food industry as they indicate that pleurocidin has potential use as a food preservative particularly in the seafood industry, against halophilic organisms as well as in low and high acid foods and may retain its activity during heat processing.
Session 29F, Food Microbiology: Control of foodborne microorganisms by antimicrobials
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