固定化米曲霉催化拆分丙氨酸消旋体的反应特性

CATALYTIC PERFORMANCE OF RACEMIC ALANINE RESOLUTION BY IMMOBILIZED Aspergillus Oryzae PELLETS

研究了溶液ｐＨ、搅拌强度、催化剂用量、底物浓度及产物浓度对固定化米曲霉催化拆分Ｎ乙酰ＤＬ丙氨酸反应的影响．结果表明，低底物浓度（Ｓ＜０２ｍｏｌ／Ｌ）时反应符合ＭＭ方程．底物浓度Ｓ＞０２ｍｏｌ／Ｌ时，有底物抑制现象．当产物浓度Ｐ＞１０ｍｍｏｌ／Ｌ时反应存在产物抑制现象．

The Aspergillus oryzae (3042) has grown up to pale yellow mycelium pellets with 1～3 mm diameter by liquid culture method and then immobilized with ethylenediamine, gelatin and glutaraldehyde. The aminoacylase in the immobilized Aspergillus oryzae pellets shows excellent activity and stability for optical resolution of NacetyDLalanine. The effects of some factors, such as pH of the reaction system, stirring intensity, amount of immobilized Aspergillus oryzae pellets, substrate concentration and product concentration, on the catalytic resolution of NacetyDLalanine were studied. The results indicate that: (1) when substrate concentration was less than 015 mol/L at 37℃, MichaelisMenten equation was suitable for this reaction, v=Vm·SKm+S, where Vm=004854 mol/(L·h), Km=001711 mol/L; (2) when substrate concentration was more than 02 mol/L, the substrate inhibition phenomenon appeared in this reaction and the reaction equation is: v=Vm·SKm+S+S2/kis, where kis=379 mol/L; (3) when product concentration was more than 10 mmol/L, the product inhibition phenomenon appeared in this reaction and the reaction equation is: v=Vm·S(Km+S) (1+P/kip), where kip=1607 mmol/L.