微生物发酵法合成高分子聚合物γ-PGA的研究

Biosynthesis of Macromolecular Polymers γ-PGA by Fermentation

摘要:

以一株γ-聚谷氨酸高产菌枯草芽孢杆菌B-115为实验菌株，分别考察碳源、氮源种类及浓度、前体物添加量、生长因子和发酵条件对γ-聚谷氨酸产率的影响。优化结果显示：碳源是6.5%的玉米糖化液，氮源是0.4%的普通蛋白胨，前体物谷氨酸钠的添加量为4%，生长因子种类及添加量分别为0.15%硫酸镁、0.006%硫酸锰、0.8%磷酸二氢钾、1.0%氯化钠、0.03%氯化钙；发酵条件为初始pH值6.5，接种量2%，装液量50mL/250mL, 150r/min, 37℃培养84h; γ-聚谷氨酸的产率可从57.85g/L提高到68.30g/L。

Abstract:

The fermentation media and culture conditions of Bacillus subtilis B-115 were optimized for producing poly γ-glutamic acid. The optimal fermentation conditions for poly γ-glutamic acid production were as follows: corn saccharification liquid 6.5%, peptone 0.4%, L-glutamate 4%, MgSO4 0.15%, MnSO4 0.006%, KH2PO4 0.8%, CaCl2 0.003%, NaCl 1%, inoculums level 2%, flask content 50mL/250mL, pH 6.5, temperatuer 37℃, rotation speed 150r?min-1, and fermentation time 84h. Under the optimal conditions, the yield of γ-PGA was increased from 57.85g/L to 68.3g/L.