EFFICIENT PRODUCTION OF GAMMA-POLYGLUTAMIC ACID BY BACILLUS-SUBTILIS (NATTO) IN JAR FERMENTERS

The large scale fermentation of gamma-polyglutamic acid (gamma-PGA) by Bacillus subtilis (natto) was done using a 30-liter jar fermenter, A stable cultivation without foaming could be done with addition of 3% N aCl to the medium, The gamma-PGA productivity became higher with incre asing speed of agitation and amounts of glutamic acid added to the bro th, Finally, we were able to obtain about 35 mg/ml of gamma-PGA under the optimum conditions, The glutamic acid added to the medium was effi ciently converted into gamma-PGA in the stationary phase, To discover the role of L-glutamic acid added to the medium for gamma-PGA biosynth esis by Bacillus subtilis (natto), the radioactivity incorporated into gamma-PGA from C-14-L-glutamic acid was measured. As a result, radioa ctive gamma-PGA was detected in the medium. Then, the glutamic acid in the medium was transported into the cells and actually polymerized as the glutamic acid unit of gamma-PGA.