Xylooligosaccharides production from a sugarcane biomass mixture: Effects of commercial enzyme combinations on bagasse/straw hydrolysis pretreated using different strategies.

Abstract

Xylooligosaccharides (XOS) are non-digestible food ingredients with prebiotic properties for selectively promoting the growth of probiotics, which provide many health benefits and several applications in the food and pharmaceutical industry. The objective of this study was to optimize the concentration of commercial hemicellulases for the production of XOS, with a 2-6 polymerization degree, using a mixture of sugarcane bagasse and straw pretreated with ionic liquid or diluted sulfuric acid. The concentrations of enzymes endo-1,4-xylanase (NS50030, Novozyme®) and α-L-arabinofuranosidase (GH51) (Megazyme®) were optimized using a central composite rotatable design (CCRD). The xylooligosaccharides (XOS) released by hydrolysis were analyzed via capillary electrophoresis and quantified with HPAEC-PAD. The XOS profile obtained from the hydrolisis of the pretreated sugarcane biomass mixture (MPSA) was similar to that obtained with the hydrolisis of MBX, which provided higher xylobiose (X2) concentration. Our results also demonstrated that pretreatment with an ionic liquid favored the requirement of lower enzyme concentration in enzymatic hydrolysis for having provided a biomass with lower lignin content than the pretreatment with dilute sulfuric acid. It required up to 20% less of the optimum concentration of the endo-1,4-xylanase mixture to achieve similar values to those obtained with the biomass pretreated with dilute sulfuric acid, representing a possible alternative to reduce enzymatic cost.