Fermentation process for preparing xylitol using mutant cells

A fermentation process for maximum production of xylitol using mutant cells Candida parapsilosis deposited to Korean Culture Center of Microorganisms with accession number KCCM-10088 comprising the steps of:

• i) fermenting xylose medium with the mutant cells wherein
• a) the mutant cell concentration by centrifugation of mutant cells grown on xylose medium or by rapid accumulation of the cells during fermentation is 15.about.35 g/L;
• b) the medium consists of 5.about.12 (w/v) % of xylose, 0.2.about.2.0 (w/v) % of yeast extract, 0.2.about.2.0 (w/v) % of ammonium sulfate, 0.2.about.2.0 (w/v) % of KH.sub.2 PO.sub.4 and 0.01.about.0.2 (w/v) % of MgSO.sub.4.7H.sub.2 O;
• c) dissolved oxygen concentration in the medium is 0.1.about.5.0 (w/v) %;
• d) redox (reduction-oxidation) potential in the medium is 50.about.150 mV;
• e) pH of the fermentation medium is 4.5.about.5.5;
• and
• f) temperature of fermentation is 27.degree..about.33.degree. C.;
• ii) removing the mutant cells and other residue from the fermentation medium;
• and
• iii) separating and recovering xylitol from the fermentation medium of step (ii).