Rice straw hemicellulosic hydrolysate was treated with five kinds of activated charcoal (powdered and granulated) in order to remove, by adsorption, toxic compounds that can be act as inhibitors in the bioconversion of xylose to xylitol, by Candida guilliermondii. Maximum values of xylitol yield factor (Y P/S= 0.67g g-1) and volumetric productivity (Q P=0.61g L-1h-1) were provided by powdered activated charcoal with small particles size (0.043mm), low granulometry (32% restrained in 325mesh) and large surface area (860m² g-1), characteristics which favoured the toxic compounds adsorption.
activated charcoal; adsorption; rice straw; hemicellulosic hydrolysate; xylitol
