Role of glucose in the bioconversion of fructose into mannitol by Candida magnoliae.

The most efficient substrate for mannitol production by Candida magnoliae HH-01 is fructose; glucose and sucrose can also be converted into mannitol but with lower conversion yields. Mannitol dehydrogenase was purified and characterized; it had the highest activity with fructose as the substrate and used only NADPH. In fed-batch fermentation with glucose, the production of mannitol from fructose ceased when the glucose was exhausted but it was reinitiated with the addition of glucose, implying that glucose plays an important role in NADPH regeneration.