Introduction
Certain Lactococcus lactis strains produce the antimicrobialpeptide nisin as a response to the presence of com-petitive bacteria, including their spores (Delves-Broughtonet al., 1996). Nisin has structure variants due to point mutation that changes its 34 amino acid chain (Fieldet al., 2008). Regardless of the variant, it can conservebiological products by preventing contamination withouttoxicity. This property has guaranteed its use in foodindustry as an established preservative