米曲霉菌体光学拆分N-乙酰-DL-苯甘氨酸的动力学研究

用液相培养基培养的米曲霉菌体直接拆分N 乙酰 DL 苯甘氨酸,并对该酶促反应进行了初步研究。考察了反应温度、pH值、金属离子、底物浓度、产物浓度等因素对反应的影响。结果表明,酶促反应的最适反应温度和pH值分别为52℃和7.0,当底物浓度小于200mmol·L-1时,反应符合Michaelis Menten方程,当底物浓度大于200mmol·L-1时,反应存在底物抑制现象。进一步研究发现水解反应也存在着产物抑制现象。

Kinetic properties of optical resolution of N-acyl-(D,L)-phenylglycine using aspergillus oryzae mycelium

Aspergillus oryzae mycelium pellets, cultured in liquid phase, were used to the optical resolution of N-acyl-(D,L)-phenylglycine. The kinetic properties of the enzyme reaction were preliminarily investigated. Some factors, such as pH and temperature of the reaction system, stirring intensity, metal ions concentration, substrate (concentration) and product concentration were studied. The result shows that the appropriate temperature and pH are 52℃ and 7.0—7.3, respectively. At low substrate concentration, the Michaelis-Menten Equation can be used to describe the enzymatic reaction. While the substrate concentration is higher than 200 mmol/L,substrate inhibition existed. The substrate inhibition constant k_(is) is 142.2 mmol/L.It also suggests that high product concentration can (cause) inhibition, and the product inhibition constant k_(ip) is 174.2 mmol/L.