title: Impact of hydrothermal pre-treatment to chemical composition, enzymatic digestibility and spatial distribution of cell wall polymers.
abstract: The effect of hydrothermal pretreatment on chemical composition, microscopic structure and enzymatic digestibility of wheat straw was studied. Wheat straw was pretreated with increasing severity to obtain series of samples with altered chemistry and structure. The hydrothermal pretreatment caused solubilisation of arabinoxylan and phenolic acids and their dimers in a temperature dependent manner with minor effects on the cellulose and Klason lignin content. In the cell wall level, the pretreatment intensified staining of cellulose and relocalised xylan in the cell walls. The distribution, properties and content of the cell wall phenolic compounds was altered as observed with phloroglucinol and autofluorescence imaging. In the enzymatic hydrolysis, the highest yields were obtained from the samples with a low xylan and diferulate content. On the cell wall structural level, the sample with the highest digestibility was observed to have intensified cellulose staining, possibly reflecting the increased accessibility of cellulose.
authors.affiliation: VTT Technical Research Centre of Finland, P.O. Box 1000, 02044 VTT, Finland.
authors.forename: Ulla
authors.initials: U
authors.lastname: Holopainen-Mantila
authors.forename: Kaisa
authors.initials: K
authors.lastname: Marjamaa
authors.forename: Zara
authors.initials: Z
authors.lastname: Merali
authors.forename: Andres
authors.initials: A
authors.lastname: Käsper
authors.forename: Peter
authors.initials: P
authors.lastname: de Bot
authors.forename: Anna-Stiina
authors.initials: AS
authors.lastname: Jääskeläinen
authors.forename: Keith
authors.initials: K
authors.lastname: Waldron
authors.forename: Kristiina
authors.initials: K
authors.lastname: Kruus
authors.forename: Tarja
authors.initials: T
authors.lastname: Tamminen
mesh_terms: D001704:Biopolymers / Q000737:chemistry*; D001709:Biotechnology / Q000379:methods*; D002241:Carbohydrates / Q000032:analysis; D002473:Cell Wall / Q000737:chemistry* / Q000187:drug effects; D002480:Cellulase / Q000378:metabolism*; D006868:Hydrolysis / Q000187:drug effects; D062385:Hydroxybenzoates / Q000032:analysis; D008031:Lignin / Q000378:metabolism; D013696:Temperature; D014908:Triticum / Q000737:chemistry; D014866:Waste Products; D014867:Water / Q000494:pharmacology*
chemical_list: D001704:Biopolymers; D002241:Carbohydrates; D062385:Hydroxybenzoates; D014866:Waste Products; D014867:Water; D008031:Lignin; D002480:Cellulase; C017616:phenolic acid