Unraveling the unique structural motifs of glucuronoxylan from hybrid aspen wood

Sammanfattning

Xylan is a fundamental structural polysaccharide in plant secondary cell walls and a valuable resource for biorefinery applications. Deciphering the molecular motifs of xylans that mediate their interaction with cellulose and lignin is fundamental to understand the structural integrity of plant cell walls and to design lignocellulosic materials. In the present study, we investigated the pattern of acetylation and glucuronidation substitution in hardwood glucuronoxylan (GX) extracted from aspen wood using subcritical water and alkaline conditions. Enzymatic digestions of GX with beta-xylanases from glycosyl hydrolase (GH) families GH10, GH11 and GH30 generated xylo-oligosaccharides with controlled structures amenable for mass spectrometric glycan sequencing. We identified the occurrence of intramolecular motifs in aspen GX with block repeats of even glucuronidation (every 2 xylose units) and consecutive glucuronidation, which are unique features for hardwood xylans. The acetylation pattern of aspen GX shows major domains with evenly-spaced decorations, together with minor stretches of highly acetylated domains. These heterogenous patterns of GX can be correlated with its extractability and with its potential interaction with lignin and cellulose. Our study provides new insights into the molecular structure of xylan in hardwood species, which has fundamental implications for overcoming lignocellulose recalcitrance during biochemical conversion.

Nyckelord

Hybrid aspen; Glucuronoxylan; Glycan sequencing; Acetylation

Publicerad i

Carbohydrate Polymers
2024, volym: 343, artikelnummer: 122434
Utgivare: ELSEVIER SCI LTD

SLU författare

• Mellerowicz, Ewa

  • Institutionen för skoglig genetik och växtfysiologi, Sveriges lantbruksuniversitet
    

UKÄ forskningsämne

Växtbioteknologi
Polymerkemi

Publikationens identifierare

• DOI: https://doi.org/10.1016/j.carbpol.2024.122434

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/131303