利用色氨酸酶酶法拆分D,L-丝氨酸制备D-丝氨酸

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。该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:温度45℃,pH=8.0,反应时间18 h,底物D,L-丝氨酸质量浓度30 g/L,色氨酸酶用量为6 g/L,经过两次转化,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001×7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%,α2D0=-15.3°(ρ=0.1 kg/L,2 mol/L HCl),总回收率为66.6%。

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

A practical method was established to resolve L-serine into L-tryptophan via tryptophanase,using D,L-serine as substrate.D-Serine could be obtained by further 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 mass concentration and 6 g/L of tryptophanase mass concentration.After two 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 and 001×7 ion-exchange resin and then recrystallized to give D-serine,the purity of which was 99.4%.The optical rotation of D-serine was-15.3°(ρ=0.1 kg/L,2 mol/L HCl) and the total separation recovery of the products was 66.6%.