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 ℃ and 39 ℃).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 reached 1.66 g/(L·h)-1 and 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.%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.
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