地衣芽孢杆菌α-淀粉酶对可溶性淀粉的酶促水解作用。

Enzymatic hydrolysis of soluble starch with an alpha-amylase from Bacillus licheniformis.

作者信息

Bravo Rodríguez V, Jurado Alameda E, Martínez Gallegos J F, Reyes Requena A, García López A I

机构信息

Departamento de Ingeniería Química, Universidad de Granada, Avd. Fuentenueva s/n, 18071 Granada, Spain.

出版信息

Biotechnol Prog. 2006 May-Jun;22(3):718-22. doi: 10.1021/bp060057a.

DOI:10.1021/bp060057a

PMID:16739954

Abstract

The enzymatic hydrolysis of soluble starch with an alpha-amylase from Bacillus licheniformis (commercial enzyme Termamyl 300 L Type DX) have been experimentally studied at pH 7.5, within the temperature range of 37-75 degrees C, at initial substrate concentrations of between 0.25 and 2.00 g/L, and enzyme concentrations of between 0.575 x 10(-4) and 13.8 x 10(-4) g/L. To follow the reaction a procedure based on the iodometric method for measuring alpha-amylase activity was used. The kinetics of the enzymatic hydrolysis was fitted to the Michaelis-Menten equation using the integral method, taking into account that the thermal deactivation of the enzyme follows a second-order kinetic. These parameters were fitted to the Arrhenius equation obtaining activation energies of 24.4 and 41.7 kJ/mol and preexponential factors of 734.9 g/L and 1.74 x 10(8) min(-1) for K(M) and k, respectively.

摘要

利用地衣芽孢杆菌的α-淀粉酶（商业酶Termamyl 300 L DX型）对可溶性淀粉进行酶水解的实验研究，实验条件为：pH 7.5，温度范围37 - 75℃，初始底物浓度在0.25至2.00 g/L之间，酶浓度在0.575×10⁻⁴至13.8×10⁻⁴ g/L之间。为跟踪反应，采用了基于碘量法测量α-淀粉酶活性的程序。考虑到酶的热失活遵循二级动力学，使用积分法将酶水解动力学拟合到米氏方程。将这些参数拟合到阿伦尼乌斯方程，分别得到米氏常数（K(M)）的活化能为24.4 kJ/mol、指前因子为734.9 g/L，以及反应速率常数（k）的活化能为41.7 kJ/mol、指前因子为1.74×10⁸ min⁻¹。