磷脂酶D的紫外诱变选育及发酵条件的优化

磷脂酶D在催化磷脂酰基交换反应中具有重要的应用价值。本文对产磷脂酶D野生链霉菌株进行紫外诱变,筛选得到一株产酶活力提高42.5%的变异株。通过摇瓶培养,对发酵条件进行探究。确定的最佳培养基组成为:葡萄糖10.0 g/L,牛肉膏和蛋白胨各5.0 g/L,MgSO4.7H2O 1.0 g/L,CaCl23.0 g/L,NaCl 2.0 g/L;表面活性剂Tween80对产酶有促进作用,其适宜浓度为0.60 g/L。在上述条件下,摇瓶发酵产酶活力达3.23 U/mL。

Ultraviolet mutagenesis breeding and fermentation conditions of phospholipase D producing strain

Phospholipase D(PLD) catalyzed transphosphatidylation reaction plays an important and useful role in synthesis of phospholipids.In the present paper,a PLD-high-producing strain was selected by ultraviolet mutagenesis from wild Streptomyces and its PLD activity was increased by 42.5% against the original strain.The PLD producing conditions for the mutant strain was investigated in shake flask fermentation.The optimized components(g/L) of culture medium were 10.0 of glucose,5.0 of beef extract,5.0 of peptone,1.0 of MgSO4.7H2O,3.0 of CaCl2,and 2.0 of NaCl.The enzyme productivity could also be enhanced by the supply of surfactant i.e.Tween 80,and its optimal concentration was 0.6 g/L.Under the above conditions,3.23 U/mL of enzyme activity was achieved in 500 mL of shake flask fermentation.