The discovery that certain cellobiose 2-epimerases (C2E) are capable of synthesizing lactulose and epilactose with high yield and selectivity has renewed the interest in their biological synthesis. In order to provide a valuable tool for the design and optimization of the synthesis of lactulose and epilactose with C2E as biocatalyst, the reaction is modeled here for the first time. Two competing reaction mechanisms, so called extended and reduced mechanisms, were proposed and their corresponding models developed. The extended mechanism was discarded because of the overfitting of the resulting model. The parameters of the reduced model were successfully estimated by no linear regression at 30, 40, 50, 60 and 70 °C, and the temperature dependence of the kinetic parameters was modeled by fitting them to Arrhenius and Van´t Hoff-type equations. The reduced model showed a good fit to experimental data within the studied temperature range, well describing the course of reactions.

某些纤维二糖 2-差向异构酶 (C2E) 能够以高产率和选择性合成乳果糖和表乳糖，这一发现重新引起了人们对其生物合成的兴趣。为了为以C2E为生物催化剂合成乳果糖和表乳糖的设计和优化提供有价值的工具，这里首次对该反应进行了建模。提出了两种竞争反应机制，即所谓的扩展机制和简化机制，并开发了相应的模型。由于所得模型的过度拟合，扩展机制被丢弃。通过在 30、40、50、60 和 70 °C 下的非线性回归成功估计了简化模型的参数，并通过将动力学参数拟合到阿伦尼乌斯和 Van´t Hoff 型方程来对动力学参数的温度依赖性进行建模。简化模型与研究温度范围内的实验数据非常吻合，很好地描述了反应过程。