BIOSYNTHESIS AND HYDROLYSIS OF POLY(GAMMA-GLUTAMIC ACID) FROM BACILLUS-SUBTILIS IFO3335

Poly(gamma-glutamic acid) (PGA) production in Bacillus subtilis IFO3335 was studied. When citric acid as a carbon source was added to a glutamic acid medium containing L-glutamic acid and ammonium sulfate, a large amount of pure PGA was produced. On the other hand, when glucose was added to the glutamic acid medium, a by-product was produced, which seemed to be a polysaccharide. Moreover, the mode of hydrolysis was investigated with PGA in aqueous solutions at 80, 100, and 120-degrees-C by monitoring the time-dependent changes in the molecular weights. Hydrolytic degradation of PGA was found to proceed through a random chain scission.