酿酒酵母by1.1b产D-(-)-扁桃酸脱氢酶的发酵条件优化

Optimization of Saccharomyces cerevisiae sp. Strain by1.1b Culture Conditions for Efficient Biosynthesis of D-(-)-mandelate Dehydrogenase

摘要:

对一株产D-(-)-扁桃酸对映选择性脱氢酶的酿酒酵母菌(Saccharomyces cerevisiae sp. strain by1.1b)发酵产酶条件进行了优化。研究各种碳源、氮源及无机盐对产酶的影响, 应用正交试验优化发酵培养基组成, 结果为: 蛋白胨 60 g/L, 麦芽糖 30 g/L, MgSO4 0.5 g/L, ZnSO4 0.01 g/L, KCl 1.0 g/L。优化后酶产量提高了7.9倍(由2.56 U/mL增至20.21 U/mL)。摇瓶培养最佳条件为: 装液量40 %, 发酵pH 6.5, 接种量10 %, 发酵温度30 ℃。考察了细胞生长及产酶的时间进程, 最佳培养时间为25 h。

Abstract:

The culture conditions of Saccharomyces cerevisiae sp. strain by 1.1b were optimized for the production of D-(-)-mandelate dehydrogenase which is useful for the asymmetric bioreduction of benzoylformate to form D-(-)-mandelate. The optimum medium (per liter)consistes of 60 g peptone, 30 g maltose, 0.5 g MgSO4, 0.01 g ZnSO4, 1.0 g KCl. After optimization of the culture medium, the enzyme production in shake flasks is enhanced from 2.56 to 20.21 U/L. The optimum fermentation conditions were determined as follows: medium volume 100 mL (i.e., 40% for a 250-mL shake flask), pH 6.5, inoculum size 10 %, temperature 30 ℃, and cultivation time 25 h.