Downstream process for xylitol produced from fermented hydrolysate

This work deals with the development of a technology for xylitol production from sugarcane hemicellulosic hydrolysate by biotechnological routes emphasizing the purification process by crystallization. The hemicellulosic hydrolysate obtained by acid hydrolysis of sugarcane bagasse, was concentrated and treated with ion-exchange resins. The fermentation (88 g/L xylose, pH 5.0, 30 h−1 oxygen transfer volumetric coefficient, 30 °C and 300 rpm stirring rate) was carried out in a 15-L bioengineering fermentator. The fermented broth was centrifuged, treated, concentrated and subsequently crystallized twice. This process resulted in xylitol in crystals with 92–94% purity.