National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
Bioresour Technol. 2011 Jan;102(2):1837-43. doi: 10.1016/j.biortech.2010.09.069. Epub 2010 Sep 29.
Cofactor-dependent biotransformations often require consumption of a secondary substrate for cofactor regeneration. Alternatively, two synthetic reactions may be coupled together through cofactor regeneration cycles. Simultaneous production of value-added products from glycerol and xylose was realized in this work through an enzymatic NAD(H) regeneration cycle involving two enzymes. Glycerol dehydrogenase (GDH) catalyzed the production of 1,3-dihydroxyacetone (DHA) from glycerol, while xylose reductase (XR) enabled the reduction of xylose to xylitol using the protons released from glycerol. Both enzymes were immobilized with P(MMA-EDMA-MAA) nanoparticles. Interestingly, the immobilized multi-enzyme system showed much improved productivity and stability as compared to native enzymes, such that the total turnover number (TTN) reached 82 for cofactor regeneration while the yield reached 160g/g-immobilized GDH for DHA production.
辅酶依赖的生物转化通常需要消耗辅助因子进行再生。或者，可以通过辅酶再生循环将两个合成反应偶联在一起。在这项工作中，通过涉及两种酶的酶 NAD(H)再生循环，从甘油和木糖同时生产出具有附加值的产品。甘油脱氢酶（GDH）催化甘油生成 1,3-二羟基丙酮（DHA），而木糖还原酶（XR）利用甘油释放的质子将木糖还原为木糖醇。两种酶都用 P（MMA-EDMA-MAA）纳米粒子固定化。有趣的是，与天然酶相比，固定化多酶体系显示出更高的生产力和稳定性，因此辅酶再生的总周转数（TTN）达到 82，而 DHA 生产的固定化 GDH 产率达到 160g/g。
