title: Interactions of arabinoxylan and (1,3)(1,4)-β-glucan with cellulose networks.
abstract: To identify interactions of relevance to the structure and properties of the primary cell walls of cereals and grasses, we used arabinoxylan and (1,3)(1,4)-β-glucan, major polymers in cereal/grass primary cell walls, to construct composites with cellulose produced by Gluconacetobacter xylinus. Both polymers associated prolifically with cellulose without becoming rigid or altering the nature or extent of cellulose crystallinity. Mechanical properties were modestly affected compared with xyloglucan or pectin (characteristic components of nongrass primary cell walls) composites with cellulose. In situ depletion of arabinoxylan arabinose side chains within preformed cellulose composites resulted in phase separation, with only limited enhancement of xylan-cellulose interactions. These results suggest that arabinoxylan and (1 → 3)(1 → 4)-β-d-glucan are not functional homologues for either xyloglucan or pectin in the way they interact with cellulose networks. Association of cell-wall polymers with cellulose driven by entropic amelioration of high energy cellulose/water interfaces should be considered as a third type of interaction within cellulose-based cell walls, in addition to molecular binding (enthalpic driving force) exhibited by, for example, xyloglucans or mannans, and interpenetrating networks based on, for example, pectins.
authors.affiliation: †The University of Queensland, ARC Centre of Excellence in Plant Cell Walls, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, Queensland 4072, Australia.
authors.forename: Deirdre
authors.initials: D
authors.lastname: Mikkelsen
authors.affiliation: †The University of Queensland, ARC Centre of Excellence in Plant Cell Walls, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, Queensland 4072, Australia.
authors.forename: Bernadine M
authors.initials: BM
authors.lastname: Flanagan
authors.affiliation: ‡The University of Melbourne, ARC Centre of Excellence in Plant Cell Walls, School of Botany and Bio21 Molecular Science and Biotechnology Institute, Melbourne, Victoria 3010, Australia.
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Wilson
authors.affiliation: ‡The University of Melbourne, ARC Centre of Excellence in Plant Cell Walls, School of Botany and Bio21 Molecular Science and Biotechnology Institute, Melbourne, Victoria 3010, Australia.
authors.forename: Antony
authors.initials: A
authors.lastname: Bacic
authors.affiliation: †The University of Queensland, ARC Centre of Excellence in Plant Cell Walls, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, Queensland 4072, Australia.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Gidley
mesh_terms: D002473:Cell Wall / Q000737:chemistry; D002482:Cellulose / Q000737:chemistry*; D041822:Gluconacetobacter xylinus / Q000737:chemistry; D014990:Xylans / Q000737:chemistry*; D047071:beta-Glucans / Q000737:chemistry*
chemical_list: D014990:Xylans; D047071:beta-Glucans; D002482:Cellulose; C085118:arabinoxylan