The influence of oxygen transfer volumetric rate (KLa) for the bioconversion of xylose intoxylitol by the yeast Candida guilliermondii FTI 20037 was evaluated using rice straw hemicellulosichydrolysate as fermentation medium. The fermentations were carried out in a bioreactor at 30°Cand 1.3 vvm, under different stirring rates (500, 300 and 200 rpm) which resulted in KLa values of52, 15.4 and 5.5 h-1 respectively. According to the results obtained, the bioconversion was dependenton the aeration rate employed, the best xylitol yield (YP/S = 0.84 g/g) being achieved with the use ofKLa = 15.4 h-1. The increase of this parameter to 52 h-1 promoted a decrease of 52% on xylitol yield,and an increase of 130% in cellular growth. The decrease of the KLa value to 5.5 h-1 did not result inany difference in the cell formation and the xylitol yield was lower than that attained with the use ofKLa = 15.4 h-1.
|Journal||Revista UniVap (Online)|
|Publication status||Published - 2003|