Author(s): Pumiput P
The steam-exploded hemicellulose hydrolysate of 100 g oil palm trunk chips was acid posthydrolysed under the condition of autoclaving at 120°C with 1%w/v H2SO4 for 30 minutes. The highest levels of xylose and glucose obtained were 8.15 g and 2.46 g, respectively. The optimal adsorption condition to remove toxic compounds in hemicellulosic hydrolysate was achieved in two steps. Five percent (w/v) of activated carbon were used in the first step for 30 minutes then 2% (w/v) activated carbon were used in the second step for 60 minutes. Comparisons were made between two sources of fermentation media, hydrolysate and pure xylose. Fermentation of the hydrolysate with Candida magnolia TISTR 5664 gave 0.08 g Yp/s of xylitol/g of xylose, whereas fermentation of pure xylose gave 0.29 g Yp/s of xylitol/g. Fermentation with C. guilliermondii FTI 20037 from the hydrolysate gave 0.12 g Yp/s of xylitol/g of xylose, whereas fermentation from pure xylose gave 0.30 g Yp/s of xylitol/g of xylose.