Electrochemical regeneration of NAD in a plug-flow reactor

Electrochemical regeneration of NAD was performed at a laboratory preparative scale to illustrate both the efficiency and intrinsic simplicity of the electrochemical method. A powerful plug-flow reactor was realized with a flow through graphite felt electrode, the ratio of the effective area of electrode/volume of reactor increased to 380 cm(2)/cm(3). This graphite-felt electrode was able to oxidize NADH coenzyme at a very low overvoltage. On the example of the gluconic acid production catalyzed by glucose dehydrogenase, current as high as 0.1 A was obtained in experience where enzymatic activity was the main limitation. In confirmation of our previous work, the results show that the yield of NADH electrochemical oxidation is better than 99.95%.