Xylitol Production from Sugarcane Bagasse Through Ultrasound- Assisted Alkaline Pretreatment and Enzymatic Hydrolysis Followed by Fermentation

Abstract

This study focused on the optimization of xylitol production from sugarcane bagasse by using response surface methodology. Xylitol was produced through a series of processes, firstly, optimization of ultrasound-assisted mild alkaline pretreatment for the xylan extraction from sugarcane bagasse followed by enzymatic hydrolysis of xylan to xylose by enzyme β-1,4-xylanase and finally microbial fermentation of xylose to xylitol using yeast (Candida guilliermondii), bacteria (Corynebacterium glutamicum) and their mixed culture for different time periods (0–96 h). Maximum xylan recovery of 12.059% (w/w) was observed at pretreatment; 0.73 M NaOH, 1:38.55 solid-to-liquid ratio and 34.77 min ultrasonication. The enzyme concentration of 400 U/g xylan at 48 h of incubation showed the highest xylose production (81.51 mg/g bagasse). Yeast (C. guilliermondii) resulted in the highest xylitol yield (Yp/s = 0.43 g/g) after 72 h. This bioprocess route can contribute as a suitable alternative for chemical methods of xylitol production.