FIGURE 2.

Average counts (log cfu/g) of L. monocytogenes in the presence (blue line) and absence (red line) of nisin treatment in a lab-scale cheese model. Calculated initial (day 0) L. monocytogenes numbers based on the average inoculum level (approximately 7 log cfu/g) are shown in black. Each cheese was inoculated with a single strain of L. monocytogenes (10403S, FSL R9-5621, FSL R9-5623, FSL R9-5624, or FSL R9-5625) to a level of approximately 7 log cfu/g. These results represent the effect of temperature (6, 14, and 22°C) on L. monocytogenes’ sensitivity to nisin. The data points are slightly offset such that the reader can clearly see each point; however, the points still correspond to 1, 7, and 14 days. All values are the arithmetic mean of three independent experiments, and error bars denote standard error. All cheese was made at pH 6.5.