Inhibition Spectrum And Application Of Pediocin

tThe optimization of culture medium,inhibition spectrum,the application on dairy for Pediocin were investigated in the present work.The theory support has provided for the application in food protection and food presevative industry by this research in the present work.Orthogonal test was used to optimize a medium for Pediocin production of Pediococcus acidilactici isolated from tradition food fermented China cabbage. The fermentation conditions have significant effects on the production and antimicrobial characteristic of Pediocins. Among all the conditions, medium ingredients, culture pH, culture temperature and culture time of fermentation are the most significant factors. The optimum medium ingredients〔g/mL〕was peptone 10,beef extract 8,gloucose 15,yeast extract powder 6,Tween 80 1,K2HPO4 3,acetate sodium 5,MgSO4 0.8,MnSO4 0.2,citrate-3-ammonium 2,optimum culture pH was 6.0, optimum culture temperature was 37℃and optimum culture time was 16h for Pediocin production of Pediococcus acidilactici are determinated in this study.The activity of Pediocin was determinated by Single-colony, Solution dilution, Well test, respectively using the optimum medium.The conbination of Well test and Solution dilution was the determination method of Pediocin activity. Several spoilage and foodborne pathogenic bacterias were chosen to evaluate the inhibitory spectrum using Well test.The results indicated that the antimicrobial activity of Pediocin on Lactobacillus plantarum and Listeria monocytogenes was found clearly and the antimicrobial activity wasnot found against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli O157, Salmonella typhi and Bacillus subtilis.To improve the antimicrobial activity, the combination of Pediocin and Nisin was tried to make application on spolilage and foodborne pahogenic bacteria.The result revealed that the antimicrobial activity increased 1.7 times when using peiocin and Nisin comparing to the activity of Pediocin and Nisin alone in the study.Then the optimum proportion of Pediocin and Nisin was discussed preliminary.The mechanism of the synergy of Pediocin and Nisin was analysed.The results has provided theoretical support for research on the mechanism of bacteriocin.The application of Pediocin in food protection and food presevative on dairy product was investigated.The results indicated that counts of L.monocytogenes inoculated in control milk decreased 1.32logCFU/mL but the addition of peidocin to milk resulted in a inhibition of L.monocytogenes,with counts 2.90logCFU/mL and 2.56logCFU/mL decline,respectively.The results indicated that Pediocin can control the growth of L.monocytogenes in dairy products.