Properties of enzymes which reduce dihydroxyacetone and related compounds in hansenula polymorpha CBS 4732

Hansenula polymorpha CBS 4732 grown on a variety of substrates contained very high activities of enzymes catalyzing the NADH-linked reduction of dihydroxyacetone, acetoin, diacetyl, acetol, methylglyoxal and acetone. The enzymes catalyzing these reductions have been purified and their kinetic properties are described. Three different enzymes were found responsible for the above-mentioned activities, namely: (1) dihydroxyacetone reductase; (2) acetone reductase; and (3) alcohol dehydrogenase. So far, the physiological function of dihydroxyacetone reductase and acetone reductase is obscure. The kinetic properties of dihydroxyacetone reductase and the regulation of the synthesis of this enzyme suggest that it does not function as a glycerol dehydrogenase.