A NOVEL FORMALDEHYDE OXIDATION PATHWAY IN METHYLOTROPHIC YEASTS - METHYLFORMATE AS A POSSIBLE INTERMEDIATE

A considerable amount of methylformate accumulated in the culture medi um of methanol-grown methylotrophic yeasts. Methylformate is considere d as an intermediate in a novel formaldehyde oxidation pathway. Throug h investigations with Pichia methanolica, methylformate formation was found to be catalysed by a new type of alcohol dehydrogenase, which wa s named methylformate synthase. When cells were grown on a relatively high concentration of methanol or exposed to a high concentration of f ormaldehyde, formation of methylformate was enhanced and the level of methylformate synthase in the cells increased. How methylformate synth ase is involved in formaldehyde oxidation and formaldehyde detoxificat ion is discussed.