Glycerol:NADP+ 2-oxidoreductase (EC 1.1.1.156) was isolated from Schizosaccharomyces pombe, purified and characterized. It had an Mr of 57,000, and SDS-PAGE revealed two polypeptides, of Mr 25,000 and 30,000. Its coenzyme requirement was satisfied exclusively by NADP. The pH optimum for glycerol oxidation was 9.5, for dihydroxyacetone reduction 6.0. Rates of oxidation with some structurally related diols were three- to six-fold lower than for glycerol, while glyceraldehyde and other carbonyl compounds showed negligible rates of reduction. Neither monovalent nor divalent cations activated the enzyme. Apparent Km and Vmax values were determined. The enzyme is similar to glycerol dehydrogenases isolated from Mucor javanicus and from Dunaliella parva but differs considerably from the glycerol:NAD+ 2-oxidoreductase of S. pombe.

The fission yeast Schizosaccharomyces pombe has been shown to produce four separate pyridine nucleotide-linked glycerol dehydrogenases (or triose reductases), distinguished by differences in their coenzyme specificity (NAD+ or NADP+) and oxidation product (dihydroxyacetone or glyceraldehyde). Evidence for four separate activities was obtained by heat inactivation studies, comparison of cells grown under different conditions, and separation and partial purification of the enzymes. One enzyme, a glycerol : NAD+ 2-oxidoreductase is repressed by glucose but not induced by glycerol and appears to function primarily in glycerol catabolism. The second, a glycerol : NADP+ 2-oxidoreductase is stimulated by growth on glucose and appears to function as a dihydroxyacetone reductase involved in glycerol synthesis. The third has the properties of a glycerol : NADP+ oxidoreductase, while the fourth is, in fact, alcohol dehydrogenase (alcohol : NAD+ oxidoreductase) which possesses weak activity as a glycerol : NAD+ 1ox idoreduc tase.

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Mutants of Schizosaccharomyces pombe unable to grow or growing very slowly on glycerol have been isolated. Some, which could grow on dihydroxyacetone, lacked, or in one mutant possessed reduced amounts of, glycerol dehydrogenase (glycerol:NAD+ 2‐oxidoreductase); others could not grow on dihydroxyacetone and lacked dihydroxyacetone kinase. Spontaneous revertants able to grow on glycerol had regained these enzymes. These results provide evidence that glycerol catabolism in S. pombe proceeds via initial dehydrogenation of glycerol followed by phosphorylation of dihydroxyacetone. There is evidence that dihydroxyacetone can be converted to a toxic product.