Abstract

Activity of the major enzymes of D-xylose metabolism in the mutants of xylose-utilizing yeasts Pachysolen tannophilus selectively producing xylitol or ethanol was studied. The xylitol-producing strain exhibited low activities of xylitol dehydrogenase, xylose reductase with preferential affinity to NADPH, NAD+-dependent malate dehydrogenase, and cytochrome c oxidase (4.40, 4.80, 1.87, and 0.28 μmol mg−1 min−1, respectively). The cells of the ethanol-producing mutants exhibited elevated activity of NADH/NADPH-xylose reductase, xylitol dehydrogenase, 1-glycerophosphate dehydrogenase, and lactate dehydrogenase to 6.80, 8.60, 4.68, and 16.48 μmol mg−1 min−1, respectively. Effect of the NADPH/NADH imbalance on ethanol production accumulation and xylitol accumulation is discussed.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call