Inhibition of temperature and Nisin on Listeria monocytogenes

The effect of different temperatures on growth of Listeria monocytogenes( LM) was studied,and Gompertz model was fit using Matlab software. In order to provide theory foundation for the development of supervisory technique,the antibacterial activity of Nisin under the different concentrations( 5,10,50,100,150 μg / m L),p H( 1,3,5,7,9) and temperatures( 45,75,95,115,121 ℃) were studied simultaneously. The results demonstrated that low temperature appeared significantly inhibiting effect,the maximum cell density was reduced by 4.3455 lg cfu / m L. The growth of LM was promoted when the concentration of Nisin was < 5 μg / m L. The bactericidal effects was the concentration of Nisin > 10 μg / m L.When the concentration of Nisin was > 150 μg / m L,it was able to kill almost all L. monocytogenes in nutritional broth during the period of 48 h cultivation. Nisin has a synergistic effect under acidic environment and a good thermal stability.