The membrane bioreactor with coenzyme recycling system.

Much attention has been paid to membrane bioreactors, especially to the newly developed charged membrane bioreactor (CMBR) for recycling the native form of the coenzyme NAD(P)H. Charged membranes with anionic groups effectively retained the free nicotinamide coenzyme due to the electrostatic repulsion between membrane and coenzyme. The capability of the CMBR was demonstrated by the continuous production of sorbitol using a multi-enzyme system of NADPH-dependent aldose reductase and glucose dehydrogenase. Several important features of the CMBR were elucidated by a theoretical model of coenzyme turnover.