Biochemical conversion of sugarcane straw hemicellulosic hydrolyzate supplemented with co-substrates for xylitol production

•Biotechnological production of xylitol is a valuable route for using sugarcane straw.•Co-substrate utilization is a strategy to improve xylitol production.•Sucrose supplementation improved xylose consumption and xylitol production.•Use of sugarcane molasses could favor bioprocess feasibility. Biotechnological production of xylitol is an attractive route to add value to a sugarcane biorefinery, through utilization of the hemicellulosic fraction of sugarcane straw, whose availability is increasing in Brazil. Herein, supplementation of the sugarcane straw hemicellulosic hydrolyzate (xylose 57gL−1) with maltose, sucrose, cellobiose or glycerol was proposed, and their effect as co-substrates on xylitol production by Candida guilliermondii FTI 20037 was studied. Sucrose (10gL−1) and glycerol (0.7gL−1) supplementation led to significant increase of 8.88% and 6.86% on xylose uptake rate (1.11gL−1h−1 and 1.09gL−1), respectively, but only with sucrose, significant increments of 12.88% and 8.69% on final xylitol concentration (36.11gL−1) and volumetric productivity (0.75gL−1h−1), respectively, were achieved. Based on these results, utilization of complex sources of sucrose, derived from agro-industries, as nutritional supplementation for xylitol production can be proposed as a strategy for improving the yeast performance and reducing the cost of this bioprocess by replacing more expensive nutrients.