A hybrid electrochemical flow reactor to couple H ₂ oxidation to NADH regeneration for biochemical reactions

Beta-nicotinamide adenine dinucleotide (NAD+/NADH) is an important enzymatic co-factor that can be efficiently regenerated using a rhodium-based catalyst as electron transfer mediator (ie, [Cp*Rh(bpy)Cl]+, where Cp* = pentamethylcyclopentadienyl and bpy 2,2-bipyridine). Here, the above mediated regeneration of NADH implemented in redox flow bioreactor hybridized with gas diffusion electrode for hydrogen oxidation. The reactor was initially optimized respect to rhodium complex NAD+ concentrations, humidification gas, rates both H2 electrolytic solution, solution pH. integration reaction consuming generated then investigated process, combining series electrochemical biochemical cell immobilized l-lactic dehydrogenase conversion pyruvate lactate. A high activity achieved turnover number up 370 h−1 regeneration. Coupled led total values 2000 6.3 × 106 bioconversion, respectively.