Glycomic profiling identifies key-structural differences in three arabinoxylan fractions from sugarcane culms

Author(s)

Garbelotti, Carolina Victal ; Grandis, Adriana ; Crevelin, Eduardo ; Buckeridge, Marcos Silveira ; de Moraes, Luiz Alberto Beraldo ; Ward, Richard John

• Document type: Journal article
• Source: Carbohydrate Polymers; v. 310, p. 13-pg., 2023-02-24.

Abstract

Sugarcane is an important food and bioenergy crop, and although the residual biomass is potentially available for biorefinery and biofuels production the complex plant cell wall matrix requires pretreatment prior to enzymatic hydrolysis. Arabinoxylans require multiple enzymes for xylose backbone and saccharide side-branch hydrolysis to release xylooligosaccharides and pentoses. The effect of arabinoxylan structure on xylooligosaccharide release by combinations of up to five xylanolytic enzymes was studied using three arabinoxylan fractions extracted from sugarcane culms by sodium chlorite, DMSO and alkaline treatments. Reducing sugar release and LC-MS detection with chemometric analysis identified different xylooligosaccharide profiles between extracts following enzyme treatments. The position and degree of side-branch decorations are determinants of enzyme activity and xylooligosaccharide diversity with the alkaline and post-sodium chlorite extracts as the most accessible and most recalcitrant, respectively, indicating acetyl substituents as a major recalcitrance factor. The complex xylooli-gosaccharide profile with the DMSO extract suggests regions with different levels of branching. Chemometric analysis identified GH10 xylanase hydrolysis products that act as substrates for other enzymes, such as alpha-glucuronidase. The strategy reported here can identify specific enzyme combinations to overcome barriers for biomass processing such as pretreatment selection, recalcitrance to enzyme digestion and optimization of reducing sugar release. (AU)

• FAPESP's process: 14/50884-5 - INCT 2014: National Institute of Science and Technology of Bioethanol
• Grantee: Marcos Silveira Buckeridge
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 16/24139-6 - Design and Characterization of Multifunctional Xylanolytic Enzymes
• Grantee: Richard John Ward
• Support Opportunities: Regular Research Grants
• FAPESP's process: 19/13936-0 - The role of xyloglucan in the cell wall architecture determination in sugarcane
• Grantee: Adriana Grandis
• Support Opportunities: Scholarships in Brazil - Post-Doctoral