纳豆芽孢杆菌液态发酵生产γ-聚谷氨酸

Production of poly-γ-glutamic acid by submerged fermentation with Bacillus subtilis natto

对纳豆芽孢杆菌CICC 20643液态发酵生产γ-聚谷氨酸(γ-PGA)的工艺进行了研究。采用单因素实验和正交实验获得了生产γ-PGA的优化培养条件:蔗糖25g/L,酵母膏5g/L,谷氨酸钠40g/L,装液量70mL/250mL锥形瓶,起始pH6.5,菌种在37℃、120r/min培养24h后,于培养基中添加5%NaCl,继续培养24h,γ-PGA的产量达到18.04g/L。实验结果表明:纳豆芽孢杆菌CICC20643是一株产γ-PGA优良菌种,在发酵过程中添加NaCl的工艺能明显提高γ-PGA的产量。

Production of poly-Y-glutamic acid （y-PGA）by cultivation of Bacillus subtilis natto CICC 20643 in submerged state had been studied. The optimum cultivation conditions through single factor and orthogonal experiments were set as follows：sucrose 25g/L, yeast extract 5g/L, glutamic acid 40g/L, initial pH at 6.5, culture volume 70mL in 250mL conical flask. Under the optimum cultivation conditions, B. subtilis natto was shaking cultivated at 37℃,120r/min for 24h,then 5% NaCI was added, and subsequently cultivated for another 24h.As a result,the yield of y-PGA was got at 18.04g/L.The experimental result showed that B.subtilis natto CICC 20643 was a strain of high-yield y-PGA and addition of NaCI in the course of cultivation could increase the yield of y-PGA.