EFFECT OF XYLITOL ON THE METABOLISM AND VIABILITY OF CANDIDA-SHEHATAE

Anaerobic D-xylose fermentations were performed with C. shehatate in t he presence of 0, 25, and 50 g/L of xylitol. D-Xylose was preferential ly utilized over xylitol and ethanol yields (Y-Etoh/S approximate to 0 .26 g/g) were unaffected by xylitol. Added xylitol did inhibit convers ion of xylose to xylitol at an external xylitol concentration of 50 g/ L; Y-Xylitol/S was reduced from 0.21 to 0.14. Cell viability declined in all of the fermentations, but was not due to the presence of xylito l. The decline in viability was attributed to oxygen deprivation, sinc e ethanol levels only reached 10.5 g/L and the decline cell viability was the same in each fermentation, regardless of the xylitol concentra tion.