Polyglutamic acid (PGA) is a polymer of the amino acid glutamic acid (GA). Gamma PGA (the form where the peptide bonds are between the amino group of GA and the carboxyl group at the end of the GA side chain) is a major constituent of the Japanese food natto. Gamma PGA is formed by bacterial fermentation. Gamma PGA has a wide number of potential uses ranging from food, medicine and water treatment. It is widely being used as a drug delivery system in cancer treatment and research is underway for its application in a treatment of type I diabetes and its potential use in the production of an AIDS vaccine.