Effect of environmental factors on antilisterial activity of nisin

Nisin، belonged to type-A lantibiotcs، is a well-known bacteriocin that applied as natural preservative in food productions such as milk and cheese. This peptide has an inhibitory effect on many of Gram-positive bacteria. Using of nisin alone and in combination with other hurdles may serves as an effective method to eliminate listeria monocytogenes and other pathogens in food industries. This study was undertaken to evaluate the effect of nisin against listeria monocytogenes in different temperatures (4، 9 and 14°C)، pH (5، 6 and 7) and NaCl concentrations (0، 1، 2 and 4). The minimum inhibitory concentration (MIC) of nisin was assessed using a broth micro-dilution method. Furthermore، for the effects of storage temperature، pH and sodium chloride concentration the Differences in Population (DP) assay were used. The MIC value of nisin was 320IU/ml. The effectiveness of nisin was pronounced at 14°C than at 9 and 4°C.