Xylitol production by Candida tropicalis in a chemically defined medium

Abstract

A chemically defined medium that included urea (5 g l⁻¹) as a nitrogen source and various vitamins was substituted for a complex medium containing yeast extract (10 g l⁻¹) in the production of xylitol by Candida tropicalis. In a fed-batch culture with the chemically defined medium, 237 g xylitol l⁻¹ was produced from 270 g xylose l⁻¹ after 120 h. The volumetric rate of xylitol production and the xylitol yield from xylose were 2 g l⁻¹ h⁻¹ and 89%, respectively. These values were about 5% lower and 4% higher, respectively, than those obtained using the complex medium. These results indicate that xylitol can be produced effectively in a chemically defined medium