OXIDATIVE ALCOHOL DEHYDROGENASE (ADH 2) FROM KLUYVEROMYCES MARXIANUS CULTURES IN DOUBLE STEP SUBSTRATE MEDIA.

Experiments with different carbon sources were performed in order to obtain oxidative alcohol dehydrogenase (ADH(2)) from Kluyveromyces marxianus. Only a double step substrate medium (glucose + reduced carbon source) gave good yields in terms of both biomass and enzymatic activity. Enzyme purification was achieved by anionic exchange chromatography and by affinity chromatography. Electrophoretic patterns of purified ADH displayed two bands for ethanol or lactate grown yeasts, and three bands for 2-propanol grown cells. Velocity constants for both the fermentative and the oxidative reaction showed a high degree of oxidative activity (maximum 94% in double step substrate media having ethanol as the second carbon source). Michaelis-Menten constants for the substrate indicated an excellent affinity for primary and secondary, saturated and unsaturated alcohols, for the enzyme.