Kinetic study and modelling of the xylitol production using Candida parapsilosis in oxygen-limited culture conditions

Kinetic studies are presented for xylitol production and growth of the yeast Candida parapsilosis ATCC 28474. The oxygen supply influence on xylitol production from xylose was investigated. No metabolic activity was detected in anaerobic conditions. In contrast, it was found that under low aeration rates (0.1-0.2 vvm), xylitol is produced. Xylitol production decreases when air flow to reactor is augmented. An unstructured model is proposed for the kinetic behaviour analysis of yeast growing in batch culture. A simplex method was used for the estimation of model parameters. The parameter confidence intervals were also calculated.