Growth of yeasts on D-xylulose 1.
Nine of eleven yeasts of different species or genera grew in the presence of air on the intermediate of D-xylose catabolism, D-xylulose (D-threo-pentulose). Growth on this substrate was efficient as judged by the optical density in stationary phase being generally similar to that after growth on glucose. Yeasts which grew on D-xylose also did so on D-xylulose, but among those which grew are included several which utilise neither D-xylose nor xylitol: Saccharomyces cerevisiae, Saccharomyces carlsbergensis, and Schizosaccharomyces pombe. Since catabolism of a sugar generally requires an initial phosphorylation step, growth of these strains suggests that they contain an enzyme which can function as a D-xylulose kinase. The D-xylulose-5-phosphate formed thereby is considered to enter the pentose-phosphate pathway. Glucose-grown inocula of S. carlsbergensis and Schizosaccharomyces pombe, and of several other yeasts, began to grow logarithmically when placed on D-xylulose with no apparent delay, or one which was minimal, suggesting that the D-xylulose kinase was already present in such cells, or was rapidly induced. Petites of S. cerevisiae did not grow on D-xylulose indicating that, in this species, mitochondria are involved in its utilisation.
D001203:Ascomycota / Q000254:growth & development; D002175:Candida / Q000254:growth & development; D003470:Culture Media; D010429:Pentoses / Q000378:metabolism*; D012440:Saccharomyces / Q000254:growth & development; D012568:Schizosaccharomyces / Q000254:growth & development; D014996:Xylulose / Q000378:metabolism*; D015003:Yeasts / Q000254:growth & development* / Q000378:metabolism
D003470:Culture Media; D010429:Pentoses; D014996:Xylulose