固定化谷氨酸脱羧酶转化γ-氨基丁酸的研究

目的用固定化谷氨酸脱羧酶转化制备γ-氨基丁酸(GABA)。方法以海藻酸钠与明胶为协同作用载体包埋固定化酶,考察影响固定化酶活性的因素,获得固定化酶的优化条件,并将酶应用于制备GABA。结果海藻酸钠、明胶、氯化钙和戊二醛浓度分别为2.5%,1.0%,3.0%和0.3%,硬化时间4 h,固定化酶的相对活性最高,酶活回收率达到65.3%。以谷氨酸为底物,固定化谷氨酸脱羧酶为催化剂,采用填充床反应器连续制备GABA,连续反应60 h,酶相对活性仍保持在初始值的76.9%,谷氨酸转化率为98.7%。结论该固定化谷氨酸脱羧酶可应用于生物转化法连续制备GABA。

Research on immobilized glutamate decarboxylase for γ-aminobutyric acid transformation

Purpose The immobilized glutamate decarboxylase(IGAD)was prepared for produing γ-aminobutyric acid(GABA).Methods Glutamate decarboxylase(GAD)was embedded-immobilized with sodium alginate and gelatin as the blending supports.Factors which affected the activity of IGAD were studied and optimum conditions were investigated.Afterwards,IGAD was applied for GABA transformation.Results 65.3% enzyme activity of IGAD could be reserved compared with unimmobilized one when the concentration of sodium alginate,gelatin,CaCl2,glutaraldehyde and solidifying time were 2.5%,1.0%,3.0%,0.3% and 4 h respectively.Afterwards,the immobilized enzyme was filled in packed bed reactor for producing GABA continuously.After 60 h reacting,the reserved enzyme activity was kept as high as 76.9% of the initial,and the transform rate of glutamate reached to 98.7%.Conclusion This IGAD can be applied for GABA biotransformation continuously.