Improvement of biotechnological xylitol production by glucose during cultive of Candida guilliermondii in sugarcane bagasse hydrolysate

Abstract

The effect of glucose on xylose-to-xylitol bioconversion by Candida guilliermondii was examined by adding it to sugarcane bagasse hydrolysate medium to obtain different glucose:xylose ratios (1:25, 1:12, 1:5 and 1:2.5). Under experimental conditions, increasing glucose:xylose ratio improved the assimilation of the xylose present in the hydrolysate by yeast, resulting in biomass increase, and in the formation of xylitol and glycerol/ethanol by-products. Maximum values of xylitol yield (0.59 g g-1) and volumetric productivity (0.53 g l-1.h-1) were obtained with glucose:xylose ratio of 1:5, resulting in the higher conversion efficiency (64.3%).