Walter Carvalho,* Júlio C. Santos, Mário A. A. Cunha and Silvio S. Silva

Chemical Engineering College of Lorena

Department of Biotechnology

Rodovia Itajubá-Lorena, km 74.5, P.O. Box 116

CEP 12600970, Lorena, S.P., Brazil

Xylitol, a polyalcohol as sweet as sucrose, is used in food and pharmaceutical industries due to its pleasant taste, non-carcinogenic properties and clinical applications. Currently, this polyalcohol is produced by chemical hydrogenation of xylose obtained through the hydrolysis of lignocellulosics. The need for purified xylose and high temperatures and pressures increases production costs. An alternative to expensive chemical hydrogenation could be biotechnological xylose-to-xylitol conversion, which allows for direct use of hemicellulosic hydrolysates under moderate conditions. The Group of Fermentative Processes (Faenquil/Brazil) has been researching the xylitol bioproduction from lignocellulosic residues. A major part of these studies focuses on the use of sugarcane bagasse as a raw material for xylitol production using the yeast Candida guilliermondii FTI 20037. Different hydrolysate detoxification procedures, fermentation systems, operation modes and yeast cultivation conditions have been studied. Recently, the research team at Faenquil began to address efforts to allow a better evaluation of the potential of immobilized cell systems. Different immobilization supports and reactor configurations have been evaluated and adequate conditions for xylitol production have been established. In this presentation, an overview of the research concerning xylitol bioproduction from sugarcane bagasse at Faenquil will be approached. Special attention will be given to the use of cells immobilized in Ca-alginate and on porous glass beads.