蒸汽爆破玉米秸秆酶解动力学

Kinetics of enzymatic hydrolysis of steam-explosion pretreated corn straw

摘要:

为了掌握蒸汽爆破玉米秸秆的酶解特性，研究了不同底物浓度、酶浓度、温度对反应速率的影响。运用米氏方程对酶解动力学过程进行拟合，结果表明，纤维素酶对该玉米秸秆的水解反应在反应前3 h符合一级反应，可用米氏方程对其进行拟合。在转速为120 r/min、酶浓度为1.2 FPU/mL、pH 5.0、温度为45 ℃时米氏常数Km为11.71 g/L，最大反应速率Vm为1.5 g/(L·h)。确立了包括底物浓度、酶浓度、温度在内的酶解动力学模型，该模型适合温度为30 ℃~50 ℃。

Abstract:

In order to learn the enzymatic hydrolysis characteristics of steam-explosion pretreated corn straw by cellulase, the effects of substrate concentration, cellulase concentration and temperature were determined. The kinetics of the hydrolysis reaction could be described with the Michealis-Menten equation, and the hydrolysis reaction obeyed the classical first-order reaction rate in the first three hours. In the condition of 45 °C and pH 5.0 and the stirring rate 120 r/min, the Michealis constant (Km) and maximum rate (Vm) for 1.2 FPU/mL of cellulase were 11.71 g/L and 1.5 g/(L·h). The kinetic model, including the parameters such as substrate concentration, enzymatic concentration and temperature, was suit for the hydrolysis reaction under the temperature range from 30 °C?50 °C.