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

摘要: 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。

Abstract: Production of poly-γ-glutamic acid (γ-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%NaCl was added, and subsequently cultivated for another 24h.As a result, the yield ofγ-PGA was got at 18.04g/L.The experimental result showed that B.subtilis natto CICC 20643 was a strain of high-yieldγ-PGA and addition of NaCl in the course of cultivation could increase the yield ofγ-PGA.