Alcohol dehydrogenase activity in Rhodotorula glutinis

Abstract

Whole-cell extracts of Rhodotorula glutinis grown on yeast extract – glucose medium contained minute quantities of NAD-dependent alcohol dehydrogenase and cinnamyl alcohol dehydrogenase. Significantly greater quantities of these enzymes, as well as an NADP-dependent alcohol dehydrogenase were contained by cells grown on the same medium with ethanol substituted for glucose as the growth substrate. Although the [Formula: see text] on ethanol of whole cells grown in ethanol medium was more than triple that of cells grown in glucose medium, there was no significant difference in the [Formula: see text] on glucose of whole cells grown in glucose or in ethanol medium. Thermal inactivation studies revealed that the NADP-dependent alcohol dehydrogenase was relatively heat-stable as compared with the NAD-dependent alcohol dehydrogenase. Gel column electrophoresis revealed three active bands of alcohol dehydrogenase activity which were identified as NAD-dependent alcohol dehydrogenase, NADP-dependent alcohol dehydrogenase, and cinnamyl alcohol dehydrogenase. The NAD- and NADP-dependent enzymes, particularly the latter, were active on higher alcohols but not on methanol.