(582l) Integrating Hydride Donor Regeneration with Size-Selective Capsules for Efficient and Sustainable Biohydrogenation

Integrating Hydride Donor Regeneration with Size-Selective Capsules for Efficient and Sustainable Biohydrogenation

Shaohua Zhang^{†,⊥}, Zhongyi Jiang^{†,⊥}, Jiafu Shi*^,‡

^†Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China;

^‡School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China;

^⊥Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China.

ABSTRACT:

Enzymatic asymmetric reductions driven by the high selective hydride transfer from enzyme cofactor play a vital role in the manufacture of pharmaceutical intermediates and fine chemicals. The hydride donor (cofactor) can be in situ regenerated by introducing a second reaction using cheap reducing agents. However, the unidirectional diffusion of cofactors between the consuming and regenerating sites would dilute its concentration and restrict the performance of biohydrogenation. Here, we show that an enclosed cycle of NAD⁺/NADH based on size-selective MOF capsules is used to integrate NADH regeneration and aldehydes/ketones hydrogenation. Specifically, alcohol dehydrogenase (ADH) is positioned in the capsule wall, while glucose dehydrogenase (GDH) and NADH are encapsulated in the lumen. The NADH regenerated by GDH is restricted in the capsule lumen and can be directly consumed by ADH without dilution by the bulk solution. The self-sufficient heterogeneous biocatalyst can continuously catalyze the hydrogenation of formaldehyde to methanol for over 72 hours without the exogenous addition of NADH and can be recycled by centrifugation for 10 times with ~80% of the initial activity retained. The integration of reactions by manipulating the diffusion of intermediates paves the way for the design of catalysts and reactors.