NADH Photosynthesis System with Affordable Electron Supply and Inhibited NADH Oxidation

Photosynthesis offers a green approach for the recycling of nicotinamide cofactors primarily NADH in bio-redox reactions. Herein, we report an NADH photosynthesis system where the oxidation of biomass derivatives is designed as an electron supply module (ESM) to afford electrons and superoxide dismutase/catalase (SOD/CAT) cascade catalysis is designed as a reactive oxygen species (ROS) elimination module (REM) to inhibit NADH degradation. Glucose as the electron donor guarantees the reaction sustainability accompanied with oxidative products of gluconic acid and formic acid. Meanwhile, enzyme cascades of SOD/CAT greatly eliminate ROS, leading to a approximate to 2.00-fold elevation of NADH yield (61.1 % vs. 30.7 %). The initial reaction rate and turnover frequency (TOF) increased by 2.50 times and 2.54 times, respectively, compared with those systems without REM. Our study establishes a novel and efficient platform for NADH photosynthesis coupled to biomass-to-chemical conversion. An innovative NADH photosynthesis system is developed, in which the oxidation of biomass derivatives is used as an electron supply module (ESM) to supply electrons and superoxide dismutase/catalase (SOD/CAT) cascade catalysis is used as a reactive oxygen species (ROS) elimination module (REM) to inhibit NADH degradation. Benefiting from the inhibition of REM, the NADH photosynthesis system exhibits a two-fold enhancement in the NADH yield compared with the system without REM.image