Nisin is a polypeptide produced by Lactococcus lactis and can be digested into amino acids by α-chymotrypsin in human intestines and stomach. It is a nonpoisonous and high efficacious food preservative/anti-microbial agent. It possesses anti-microbial activity against a wide range of gram-positive bacteria, particularly those that produce spores, such as clostridium botulinum, staphylococcus aureus, streptococcus hemolyticus, listeria monocytogenes, bacillus stearothermophilus, bacillus subtilis etc.

The use of Nisin, as a food preservative, can greatly decrease the required temperature and shorten the time in food heating processing, which could not only improve the nutritional value, appearance, flavor and texture of foods, significantly prolong the shelf-life, but also save energy greatly and lower the product cost. Now Nisin has been used in a wide range of processed foods, e.g. cured meat, dairy products, plant protein foods, canned foods, and heat-treated/air-tightly packed foods, etc. It can also be used in the area of cosmetics, medicines and health products.