Dihydroxyacetone Reductase Responsible for Less-aerobic Growth of a Methylotrophic Yeast, Hansenula ofunaensis

Abstract

Correlation between the activity of dihydroxyacetone reductase (DHAR) and the intracellular content of glycerol in a methylotrophic yeast, Hansenula ofunaensis, was observed when it was grown on methanol. The DHAR activity and the glycerol synthesis were low in the presence of a high concentration of NaCl or KC1. DHAR activity increased with growth under less-aerobic conditions in the methanol medium. The less-aerobic conditions after aerobic cultivation increased the glycerol synthesis. Methanol was the most effective carbon source for DHAR synthesis and glycerol did not repress the synthesis. From these results, it was concluded that DHAR in methanol-grown cells of H. ofunaensis might be responsible for the growth under less-aerobic conditions, but not for that under salt stress conditions or for glycerol synthesis itself.