title: Occurrence of multiple forms of alcohol dehydrogenase in Penicillium supplemented with 2,3-butanediol.
abstract: The NAD-dependent oxidation of ethanol, 2,3-butanediol, and other primary and secondary alcohols, catalyzed by alcohol dehydrogenases derived from Penicillium charlesii, was investigated. Alcohol dehydrogenase, ADH-I, was purified to homogeneity in a yield of 54%. The enzyme utilizes several primary alcohols as substrates, with Km values of the order of 10(-4) M. A Km value of 60 mM was obtained for R,R,-2,3-butanediol. The stereospecificity of the oxidation of 2-butanol was investigated, and S-(+)-2-butanol was found to be oxidized 2.4 times faster than was R-(-)-2-butanol. The reduction of 2-butanone was shown to produce S-(+)-2-butanol and R-(-)-butanol in a ratio of 7:3. ADH-I is the primary isozyme of alcohol dehydrogenase present in cultures utilizing glucose as the sole carbon source. The level of alcohol dehydrogenase activity increased 7.6-fold in mycelia from cultures grown with glucose and 2,3-butanediol (0.5%) as carbon sources compared with the activity in cultures grown on only glucose. Two additional forms of alcohol dehydrogenase, ADH-II and ADH-III, were present in the cultures supplemented with 2,3-butanediol. These forms of alcohol dehydrogenase catalyze the oxidation of ethanol and 2,3-butanediol. These data suggest that P. charlesii carries out an oxidation of 2,3-butanediol which may constitute the first reaction in the degradation of 2,3-butanediol as well as the last reaction in the mixed-acid fermentation. Alcohol dehydrogenase activities in P. charlesii may be encoded by multiple genes, one which is expressed constitutively and others whose expression is inducible by 2,3-butanediol.
mesh_terms: D000426:Alcohol Dehydrogenase; D000429:Alcohol Oxidoreductases / Q000145:classification / Q000302:isolation & purification*; D002072:Butylene Glycols / Q000378:metabolism*; D002384:Catalysis; D055598:Chemical Phenomena; D002621:Chemistry; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D007700:Kinetics; D008970:Molecular Weight; D009243:NAD / Q000378:metabolism; D010407:Penicillium / Q000201:enzymology*; D013237:Stereoisomerism; D013379:Substrate Specificity
chemical_list: D002072:Butylene Glycols; D009243:NAD; D000431:Ethanol; C026978:2,3-butylene glycol; D000429:Alcohol Oxidoreductases; D000426:Alcohol Dehydrogenase