Abstract:

The membrane fraction of Gluconobacter oxydans DSM 2003 was collected by ultra-centrifugation, and an enzyme with dehydrogenase activity to 1,2-propanediol was isolated from the membrane fraction and purified by CM-cellulose column chromatography. The purified enzyme was composed of two subunits with molecular weights of approximately 80 and 50 kD, respectively. Meanwhile, this enzyme was confirmed to be alcohol dehydrogenase (ADH) by mass spectrometry. The optimal reaction pH and temperature for this enzyme were 5.5－6.0 and 30 ℃, respectively. Although this enzyme exhibited a broad substrate spectrum including primary and secondary alcohols, alcohols containing 3 hydroxyl groups and more failed to be oxidized by it. The activity of this enzyme was inhibited by most of the selected metal ions, especially by Cu2+ and Fe3+.

Key words: Gluconobacter oxydans, alcohol dehydrogenase, purification, identification, characterization