Nisin is a polypeptide produced by Lactococcus lactis. It can be fast hydrolyzed into amino acid in chymotrypsin and pH condition of human. It doesn't change normal bacterial and occur the resistance problem like other antibiotics do. It even prevents cross-resistance with other antibiotics. It's a pure natural food preservative with high efficiency, non toxicity, safety and excellent performance. It works effectively to inhibit Gram positive bacterium, e.g. Bacillus stearothermophilus, Bacillus cereus, Staphylococcus aureus, Listeria, Clostridium botulinum and so on. It especially works for bacterium which produce spore, so Nisin can help to decrease the Sterilization temperature, shorten sterilization time and basically retain natural nutrients, special flavor, color of food and save energy at the meantime. WHO/FAO JECFA approved it as a safe food preservative.