[Polyol dehydrogenases in mycobacteria (author's transl)]

Contrary to the the tubercle bacilli (H37Ra, BCG), Mycobacterium phlei, grown on Sauton medium, formed the NAD+ dependent dehydrogenases that catalyse the oxidation of ribitol, sorbitol and mannitol. These enzymes were separated by chromatography on DEAE-cellulose and Sephadex G-200. In the present work we have principally studied the ribitol dehydrogenase. All the experiments for induction of the ribitol dehydrogenase in H37Ra or BCG were negative; whereas after the adaptation of M. phlei to ribitol, the specific activity of this enzyme increased in the supernatants more than 100 per cent. The ribitol dehydrogenase of M. phlei reduced NAD+ not only in the presence of ribitol but also (though to a lesser extent) in the presence of erythritol and glycerol. Other properties studied concerning this enzyme and the reaction it catalyses were: pH dependence, equilibrium constant, Km and sensitivity towards the inhibitors of the thiol groups.