Nisin natural antimicrobial is used to control bacterial spoilage in both heat processed and low pH foods. Nisin is a natural polypeptide antibacterial produced by strains of Lactococcus lactis subsp lactis. Nisin is effective against a wide range of Gram-positive bacteria and is particularly effective against the heat resistant spores produced by Gram-positive Bacillus and Clostridium spp. Nisin has no effect against Gram-negative bacteria, yeasts or moulds. Nisin is manufactured from the fermentation of a milk-based medium by Lactococcus lactis subsp. lactis. The nisin from this fermentation is concentrated, dried and standardized with sodium chloride to produce Nisin, which has a known and consistent level of nisin activity. Nisin is soluble in aqueous environments and is most stable to heat in acidic conditions. At typical usage levels, Nisin does no affect the colour or flavour of the finished product.