PRETREATMENT OF SUGAR-CANE BAGASSE HEMICELLULOSE HYDROLYSATE FOR XYLITOL PRODUCTION BY YEAST

A total of six known xylitol-producing yeast strains were screened for production of xylitol from xylose. Candida sp. 11-2 proved to be the best producer. It was chosen to study its ability to produce xylitol f rom hemicellulose hydrolysate derived from sugar cane bagasse. The hyd rolysate was prepared by dilute sulfuric acid (2-3% [w/v]) hydrolysis, with a high-solid, low-liquid ratio followed by leaching. Owing to th e inhibitors present in the hydrolysate, different treatments were stu died to overcome its effect. In order to reach higher xylitol producti vity, treated hydrolysates were concentrated by vacuum evaporation in rotavapor to provide a higher initial xylose concentration. After trea tment, Candida sp. 11-2 was able to ferment xylose in hemicellulose hy drolysate to produce xylitol.