Different processing charachteristics of wheat straw fractions
Thursday, May 1, 2014: 8:25 AM
Grand Ballroom A-C, lobby level (Hilton Clearwater Beach)
Claus Felby, Faculty of Science, University of Copenhagen, Frederiksberg C, Denmark, Lisbeth G. Thygesen, Faculty of Science, University of Copenhagen, Copenhagen, Denmark and Heng Zhang, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark
Wheat is one of the most widely cultivated cereals, and the residue is a potential resource for 2nd generation biofuel production. Various thermochemical pretreatment strategies and cellulosic enzymes have been developed and improved to process wheat straw. However, detailed knowledge on how the organ, tissue or cell wall level responds to pretreatment and hydrolysis is limited, but is important to move research and industrial processing forward.
This study investigates how the chemical and structural composition of leaf and stem reacts to hydrothermal pretreatment and hydrolysis. Hydrothermal pretreatment showed fundamentally different effects on the enzymatic accessibility of the two fractions, where the parenchymatic tissue of the leaf is readily digested by the enzymes. Various spectroscopic methods were used to compare the accessibility of the cellulose, and to determine the relative crystallinity of leaf and stem. An interesting observation using deuterium exchange was the different distribution of intramolecular and intermolecular hydrogen bonds in leaf and stem tissues, which may point to basic structural differences in the cell wall matrix providing new insights into the basic mechanisms of recalcitrance.
Furthermore, a survey of twenty-one wheat straw cultivars found a large variation of leaf/stem ratio, which shows a potential for breeding of biorefinery adapted wheat cultivars.