Xylitol production in a bubble column bioreactor: Influence of the aeration rate and immobilized system concentration

This work evaluated the xylitol production from sugarcane bagasse hemicellulosic hydrolysate in a bubble column bioreactor using cells of the yeast Candida guilliermondii immobilized in calcium-alginate. The fermentation runs were performed according to a 22 full factorial design with three replicates at the center point in order to determine the effect of the variables: aeration rate (0.66–1.33vvm) and immobilized system concentration (20–40% v/v), on the efficiency of xylose-to-xylitol conversion and on the xylitol volumetric productivity.

The results indicated a significant influence of both variables on xylitol production. The highest conversion efficiency (41%) was attained using 1.33vvm aeration rate and 40% immobilized system. Under these conditions, the volumetric productivity was 0.21gl−1h−1.