Nisin is a polypeptide produced by Lactococcus lactis and can be digested into amino acids by a-chymotrypsinin in human intestines and stomach. The use of Nisin will not affect the normal bacterial community, nor produce the drug resistance or chiasmatic resistance as it happened when the antibiotics used. Nisin 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, which are the major food spoilage organisms, 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 heat 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.