Bioprocess Engineering

, Volume 11, Issue 4, pp 129–134

Microbial production of xylitol from D-xylose using Candida tropicalis

  • S. S. da Silva
  • A. S. Afschar
Originals

DOI: 10.1007/BF00518734

Cite this article as:
da Silva, S.S. & Afschar, A.S. Bioprocess Engineering (1994) 11: 129. doi:10.1007/BF00518734

Abstract

Candida tropicalis DSM 7524 was used to produce xylitol from d-xylose. The fermentation conditions were optimized during continuous cultivation. The strain employed showed no great dependence upon temperature in a range between 30° C and 37° C. It achieved its best yield of xylitol from d-xylose at a pH value of 2.5. Such low pH values allow non sterile cultivation, which is a major economic factor. With an oxygen uptake rate of 0.8–1 ml oxygen per litre culture medium, the C. tropicalis produce xylitol at a yield of between 77% and 80% of the theoretical value. Higher yeast extract concentrations prevent the conversion of d-xylose into xylitol. d-xylose acts as a growth inhibitor in higher concentrations. The maximum xylitol yield was reached at a d-xylose concentration of around 100 g/l. In a non sterile batch culture with substrate shift 220 g/l xylitol were produced from 300 g/l d-xylose at a xylitol productivity rate of 0.37 g/(lh). In order to increase the specific yield, C. tropicalis was immobilised on porous glass and cultivated in a fluidized bed reactor. In a continuous non sterile cultivation with immobilised cells 155 g/l d-xylose produced 90–95% g/l xylitol with a productivity of 1.35 g/(lh).

Copyright information

© Springer-Verlag 1994

Authors and Affiliations

  • S. S. da Silva
    • 1
  • A. S. Afschar
    • 2
  1. 1.GBF-Gesellschaft für Biotechnologische Forschung mbHBraunschweigGermany
  2. 2.CEBIQ-Center for Biotechnology and Chemistry, Faculty, of Chemical Engineering of LorenaUniversity of Sao PauloLorena Sao PauloBrazil