Xylitol from wood: study of some operational strategies

Raw or alkali-extracted Eucalyptus globulus wood samples were treated with aqueous sulphuric acid in order to obtain xylose solutions. After neutralization and nutrient addition, the hydrolysates were used as culture media for the production of xylitol by the yeast Debaryomyces hansenii NRRL Y-7426. Several alternatives were considered for producing xylitol from wood. Either the original wood or the hydrolysates were subjected to selected treatment stages (NaOH extraction, concentration by evaporation or treatment with sulphite-bisulphite solutions). The results obtained are discussed in terms of volumetric productivity and product yield, and compared with data presented in the literature.