Processes for production of glycerol, aldehydes and polyols by using the methylotrophic function of yeasts were developed. The unique metabolism of glycerol involving a new enzyme, dihydroxyacetone reductase, was applied to the glycerol production employing a glycerol-negative mutant. Alcohol oxidase activity was improved and used for production of aldehydes from corresponding alcohols. NADH generation during methanol oxidation was coupled with hydrogenation of sugars to produce sorbitol, iditol and xylitol.