Xylitol production by a methanol yeast,Candida boidinii (Kloeckera sp.) No. 2201

A methanol yeast, Candida boidinii no. 2201, could produce xylitol and also d-xylulose during cultivation on d-xylose medium. These fermentative products were identified by high performance liquid chromatography. A large amount of xylitol was obtained from a d-xylose medium containing ammonium acetate and yeast extract at the initial pH of 7.0. Maximum productivities of xylitol and enzymes concerned with the production were observed after 4–5 d of cultivation. A d-xylose (100 g/l) medium supplemented with 2% (v/v) methanol gave higher amounts of xylitol (48.5 g/l) and d-xylulose (3.3 g/l). Enzyme activities for d-xylose reduction, d-xylulose reduction, d-xylose isomerization, and d-xylulose phosphorylation, which could be involved in the xylitol production, were measured in cell-free extracts during cultivation and a possible pathway of xylitol production was discussed.