Immobilization of alcohol dehydrogenase, malic dehydrogenase and dextran—NAD+ within nylon-polyethyleneimine microcapsules: preparation and cofactor recycling

A detialed preparative procedure is described for the preparation of nylon—polyethyleneimine microcapsules containing yeast alcohol dehydrogenase (EC 1.1.1.1), malic dehydrogenase (EC 1.1.1.37), and a soluble dextran bound NAD+ derivative. In the presence of substrate, the microencapsulated dextran—NAD+ can be recycled at a rate of 2 cycles per minute. A column of the microcapsules forms a continuous flow system. Efficient and stable recycling rates could be maintained continuously when used for 3 h. Each column of microcapsules when reused several times during a two-week period still retained 40% of its original activity.