荞麦淀粉的真菌淀粉酶酶解动力学研究

    Kinetics of buckwheat starch enzymatic hydrolysis with fungal-α-amylase

    • 摘要: 为掌握真菌α-淀粉酶对荞麦淀粉的酶解特性,该文研究了不同底物浓度、酶浓度、pH值及温度对水解反应速率的影响,运用米氏方程对水解动力学过程进行描述和拟合,用Lineweaver-Burk和Wilkinson统计法求解动力学参数。结果表明,真菌α-淀粉酶对荞麦淀粉的水解反应初期遵循一级反应规律,可用米氏方程对水解动力学过程进行描述和拟合,在酶浓度为0.5 U/mL、pH值5.5、温度为55℃时米氏常数Km为5.470 mg/mL,最大反应速率Vm为1.587 mg/(mL·min)。确立的包括底物浓度、酶浓度、水解温度在内的荞麦淀粉酶水解动力学模型,在303.15~333.15 K的温度范围内适用。

       

      Abstract: In order to master the enzymatic hydrolysis characteristics of buckwheat starch by fungal-α-amylase, the effects of substrate concentration, enzymatic concentration, pH value and temperature on reaction velocity were determined. The kinetics of the hydrolysis reaction were described with the Michaelis-Menten equation, and the kinetic parameters were calculated by the Lineweaver-Burk and Wilkinson methods. The results show that buckwheat starch hydrolysis by fungal-α-amylase obeys the classical first-order reaction rate, and the kinetics can be modeled by Michaelis-Menten equation. In the condition of 55℃ and pH 5.5, the Minchaeli constant(Km) and maximum rate(Vm) for 0.5 U/mL of fungal-α-amylase are 5.470 mg/mL and 1.587 mg/(mL·min). The kinetic model, including the parameters such as substrate concentration, enzymatic concentration and temperature, is suit for the hydrolysis under the temperature range from 303.15 K to 333.15 K.

       

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