rProROL脂肪酶催化大豆油水解反应的半经验动力学模型

Semi-empirical kinetic model of hydrolysis of soybean oil catalyzed by recombinant Rhizopus oryzae lipase

以大豆油水解反应为模型,考察了缓冲液p H(5.0~7.0)及其添加量(5%~30%)、酶添加量(10~50U/g)和反应温度(30~50℃)对r ProROL脂肪酶(recombinant Rhizopus oryzae lipase with prosequence,r ProROL)催化大豆油水解的影响,并基于反应条件假设该酶促反应遵循一级反应,建立了酶催化大豆油甘油三酯(triglyceride,TAG)水解反应的半经验动力学模型(Hr=Hr_i×(1-e^(-kt))+Hre),并通过规划求解得到了不同反应条件下的方程系数。结果显示,通过对比TAG水解率的实验实测值与由动力学方程计算的预测值,两者的相关系数高达0.999 1,验证了该反应符合一级反应;不同反应条件对方程系数(k、Hri、Hre)的影响程度各不同,反映了该酶催化大豆油水解过程中反应速率常数(k)及TAG水解程度的变化规律,为该酶催化大豆油水解过程优化控制提供了直接的数据支持。

Soybean oil was hydrolyzed by using a recombinant Rhizopus oryzae lipase containing prosequence（ r ProROL）,and effect of buffer p H（ 5. 0- 7. 0）,buffer amount（ 5%- 30%）,lipase amount（ 10- 50 U/g） and reaction temperature（ 30- 50℃） were investigated. Based on the employed reaction conditions,r ProROL-catalyzed hydrolysis was assumed as a first-order reaction,and a semi-empirical kinetic model for the hydrolysis rate（ Hr） was established,and the model was presented as follows： Hr = Hr_i×（ 1- e^（- kt）） ＋ Hre. Parameters including reaction rate constant（ k）,theoretical hydrolysis rate（ Hri） and difference value（ Hre） related to Hr and Hri were solved using a programming. The results showed that the correlation coefficient between hydrolysis rates of soybean oil obtained from experiments and predicted by the established kinetic model was 0. 999 1,which verified that the r ProROL-catalyzed hydrolysis of soybean oil was a first-order reaction and the established model was effective. In addition,reaction rate constant（ k）,Hreand Hriwere affected by various conditions,indicating changes in k and Hr during the hydrolysis of soybean oil catalyzed by r ProROL. These results may provide information for optimization and monitoring of r ProROLcatalyzed hydrolysis process.