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 from hemicellulose hydrolysate derived from sugar cane bagasse. The hydrolysate was prepared by dilute sulfuric acid (2-3% [w/v]) hydrolysis, with a high-solid, low-liquid ratio followed by leaching. Owing to the inhibitors present in the hydrolysate, different treatments were studied to overcome its effect. In order to reach higher xylitol productivity, treated hydrolysates were concentrated by vacuum evaporation in rotavapor to provide a higher initial xylose concentration. After treatment, Candida sp. 11-2 was able to ferment xylose in hemicellulose hydrolysate to produce xylitol.