TITLE:
Optimization of Fermentation Conditions for γ-PGA Production by Bacillus subtilis QM3
AUTHORS:
Bingqi Dong, Qingping Hu
KEYWORDS:
B. subtilis QM3, γ-PGA, Condition Optimization
JOURNAL NAME:
Open Access Library Journal,
Vol.11 No.2,
February
29,
2024
ABSTRACT: γ-Polyglutamic acid (PGA) is a high molecular polymer polymerized by glutamic acid (Glu). In the γ-PGA production pathway, the production of γ-PGA by microbial fermentation in the laboratory has become the main way of γ-PGA synthesis because of its convenient operation, low cost, and considerable effect. In order to find the high yield of γ-PGA strain and increase the yield of γ-PGA produced by microorganisms, B. subtilis QM3 was used as the experimental material to optimize the nutrition conditions and culture conditions of γ-PGA production by QM3 fermentation. The results showed that the optimum medium composition and fermentation conditions for the production of γ-PGA by B. subtilis QM3 fermentation were as follows: glucose 4%, yeast extract 1%, sodium glutamate 1%, MgSO4∙7H2O 0.025%, K2HPO4 0.2% department NH4Cl 0.3%, initial pH 6, 250 ml flask, liquid volume 30 ml, 121˚C sterilization 20 min, inoculum 2%, shaker speed 220 rpm 42˚C shaker culture for 72 hours, at this time, the yield of γ-PGA was the highest, reaching 124.58 g∙L.