Merck, SBR00021-1ML, Nisin

Application
Due to its wide range of antimicrobial activity, nisin is used as a shelf-life extender in a broad range of dairy and non-dairy products.
Biochem/physiol Actions
Nisin (Nisaplin) is produced by Lactococcus lactis. It is an effective lantibiotic peptide bactericidal agent. Nisin is a broad spectrum antimicrobial bacteriocin which affects Gram-positive bacteria, however, it has little or no effect on Gram-negative bacteria, yeasts or fungi.

It was demonstrated that nisin has capability to inhibit the growth of almost all tested Gram-positive beer-spoilage bacteria. Of 122 Gram-positive bacteria strains (predominantly Lactobacilli and Pediococci), 93% were sensitive to 100 units of nisin. In contrast, out of the 32 Gram-negative strains tested, only the genus Flavobacter proved to be affected by nisin.

Nisin exerts its antimicrobial activity by binding to lipid II which is a membrane-bound advanced intermediate involved in the biosynthesis of bacterial cell wall. By doing so, nisin sequesters lipid II from its functional location. In addition, the nisin-lipid II complex leads to formation of pores in the membrane causing cell death.