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United States Department of Agriculture

Agricultural Research Service

Title: Modelling Cross-Links Within Wall Matrices:impact Upon Polysaccharide Degradation

Authors
item Hatfield, Ronald
item Grabber, John
item Ralph, John

Submitted to: Keystone Symposium on Extracellular Matrix of Plants: Molecular, Cellular A
Publication Type: Abstract Only
Publication Acceptance Date: March 21, 1996
Publication Date: N/A

Technical Abstract: Degradation of plant cell wall polysaccharides in biomass conversion processes is probably limited by cross-linking of wall polymers. Cell walls from maize suspensions were used to assess the impact of ferulate cross-linking upon wall degradation. Supplying H202 to walls containing bound peroxidases increased the proportion of dehydrodiferulates to total ferulates from 20 to 45%. Approximately 45% of the dehydrodiferulates wer coupled by 8-5 linkages, with 8-8, 8-O-4, and 5-5 types each comprising 15- 20% of the total. Incorporation into synthetic wall-bound lignin was extensive for ferulate monomers (94%) and dehydrodimers (5-5, 98%; 8-04, 89%; 8-8, 81% and 8-5, 78%). Reduction of ferulate cross-links significantly improved the degradation of structural polysaccharides by fungal hydrolases (e.g., see figures for lignified walls). These results indicate that genetic manipulation of ferulate concentrations within grass walls would improve enzymatic degradation of structural polysaccharides.

Last Modified: 4/17/2014
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