Derived microorganisms containing foreign DNA encoding for nisin production and a method for producing the derived microorganisms by transferring DNA to a recipient microorganism are described. The recipient microorganisms are preferably bacteria lacking in the ability to produce nisin. Nisin inhibits the growth of spoilage bacteria and is used in various materials for preservation, including foods and particularly at refrigeration temperatures. Nisin is also used in animals for improving the health of the animal. The foreign DNA is obtained from a donor microorganism and encodes for nisin production when transferred to the recipient microorganism.