解淀粉芽孢杆菌YP-2生产γ-聚谷氨酸的变温发酵条件研究

Condition of variable temperature fermentation of poly-γ-glutamic acid production by B.amyloliquefaciens YP-2

考察了不同温度(31℃,33℃,35℃,37℃,39℃)恒温发酵时间对解淀粉芽孢杆菌YP-2(B.amyloliquefaciens YP-2)发酵生产γ-聚谷氨酸产量的影响.通过对不同温度下γ-聚谷氨酸发酵的动力学分析,制定了阶梯式温度调控方案:0~4 h,35℃;4~7 h,31℃;7~10 h,33℃;10~26 h,37℃;26~60 h,31℃.在此变温发酵条件下,最大菌体生产率达到1.66 g/(L·h)-1,γ-聚谷氨酸最大产量达到29.50 g/L,分别比最优的恒温37℃发酵条件下的产量提高了4.4%和11.8%.这表明较之恒温发酵,变温发酵工艺有效提高了解淀粉芽孢杆菌YP-2发酵生产γ-聚谷氨酸的产量.

The effects of constant temperature fermentation time on poly-γ-glutamic acid（ γ-PGA） production by B. amyloliquefaciens YP-2 was investigated under different temperatures（ 31 ℃,33 ℃,35 ℃,37 ℃ and39 ℃）. The scheme of step-wise temperature control（ 0 - 4 h,35 ℃; 4 - 7 h,31 ℃; 7 - 10 h,33 ℃; 10 -26 h,37 ℃; 26 - 60 h,31 ℃） was formulated following the kinetic analysis of γ-PGA fermentation. Under the variable temperature fermentation condition,the maximum cell productivity and γ-PGA yield reached1. 66 g/（ L·h）-1and 29. 50 g/L,respectively,which was 4. 4% and 11. 8% higher than those in optimal constant temperature at 37 ℃. The results indicated the variable temperature fermentation effectively improved the γ-PGA production by B. amyloliquefaciens YP-2 comparing with constant temperature fermentation.