谷氨酰胺转胺酶发酵条件的优化研究

The optimization of fermentation conditions for microbial transglutaminase (MTG)

通过优化种子培养条件和发酵培养基组分使谷氨酰胺转胺酶产酶水平有了很大的提高。确定种龄为 2 0～ 2 4h ,接种量 8%左右。发酵培养基含淀粉 15g L、葡萄糖 15g L、蛋白胨 2 5g L、酵母膏 3g L、无水硫酸镁 2g L、磷酸氢二钾 2g L、无水磷酸二氢钾 2g L ,2 4～ 2 8h添加质量浓度为 0 .5 %的硫酸铵。在 10L发酵罐实验中 ,验证了溶解氧对MTG合成至关重要 ,确定较适宜通气量 1∶1.2 5vvm ,搅拌转速 30 0r min ,最高产酶单位最终稳定在 3.2u mL ,放罐时间在 4 4～ 4

High output of MTG was achieved after the optimization of the incubation condition of seed and the fermentation medium. It was confirmed that the age of seed for inoculating was 20～24 h and the inoculum size was 8%.The fermentation medium contains 15 g/L of starch, 15 g/L of glucose, 25 g/L of peptone, 3 g/L of yeast extract, 2 g/L of MgSO 4, 2 g/L of K 2HPO 4, 2 g/L of KH 2PO 4, 0.5% of (NH 4) 2SO 4 was added during 24～28 h. The dissolved of oxygen level was also important for the biosynthesis of MTG in the 10 L fermentor. The proper aeration rate was 1.25 vvm, and the agitation speed was 300 r/min. The highest enzyme activity of MTG reached 3.2u/mL during 44～46 h.