利用色氨酸酶酶法拆分D,L-丝氨酸制备D-丝氨酸

Preparation of D-Serine by enzymatic resolution of D,L-Serine using Tryptophanase

摘要:

以D,L-丝氨酸为底物，采用色氨酸酶将L-丝氨酸转化为L-色氨酸，并进一步分离纯化拆分得到D-丝氨酸。本文对色氨酸酶酶法拆分条件进行了响应面优化，酶促反应最佳条件为：45℃，pH 8.0，反应时间18h，底物D,L-丝氨酸质量浓度30g/L，色氨酸酶用量为6g/L，经过两次转化，产物L-丝氨酸的总转化率可达95.4%。酶促反应液经NKA-II型大孔吸附树脂与0017强酸性阳离子交换树脂纯化，重结晶后得到D-丝氨酸，化学纯度99.4%， =-15.3，总回收率为66.6%。

Abstract:

A practical method was established to resolute L-Serine into L-Tryptophan via Tryptophanase, using D,L-Serine as the substrate. D-Serine could be obtained after isolation and purification. Response surface methodology was used to optimize the conditions of the enzymatic resolution. And the optimum conditions were: 45℃, pH 8.0, 18 hours, 30 g/L of substrate concentration and 6 g/L of Tryptophanase concentration. After twice similar reactions, the total conversion rate of L-Serine could be up to 95.4% .The products were separated and purified on NKA-II macroporous absorption resin, 001×7 ion-exchange resin and recrystallized at the end. The purity of the products was 99.4%.The optical rotation of D-Serine was -15.3°(C=10,2N HCl) and the total separation recovery of the products was 66.6 % .