Methylotrophic yeasts metabolize methanol as a carbon and energy source to carbon dioxide and water
by the direct oxidation pathway. Since the first report of methylotrophic yeasts by Ogata in 1969, these organ- isms have been studied from both a physiological in- terest and industrial applications (Demain et al., 1998). Some are being used as the principal biocatalyst for the production of useful compounds and as hosts for gene expression (Gellissen, 2000; Sakai et al., 1996). Most of known methylotrophic yeasts belong to the two genera Pichia and Candida (Barnett et al., 2000;