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United States Department of Agriculture

Agricultural Research Service

Title: Altering Lignin Composition, Structure and Cross-Linking: Potential Impact on Cell Wall Degradation

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

Submitted to: American Chemical Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: March 28, 1996
Publication Date: N/A

Technical Abstract: Monolignols were polymerized into primary walls isolated from Zea mays cell suspensions by wall-bound peroxidase and hydrogen peroxide to form dehydrogenation polymer-cell wall (DHP-CW) complexes. Complexes were degraded for 72 h by hydrolases from Trichoderma reesei and Aspergillus niger. Complexes formed with p-coumaryl, coniferyl or sinapyl alcohols were e60% more degradable than complexes formed with coniferyl aldehyde. Selective reduction of aldehydes with borohydride largely eliminated degradability differences, suggesting that high hydrophobicity of aldehyde containing DHPs limited the degradation of complexes. Complexes formed by "bulk" polymerization of coniferyl alcohol at pH 5.5 were up to 27% more degradable than complexes formed by "end-wise" polymerization of coniferyl alcohol at pH 4.0. When ferulate cross-linking of polysaccharides to DHPs was reduced by 70%, the degradation of complexes was increased by 20%. Modifications in lignin-matrix interactions had the greatest impact on the degradability of arabinoxylans.

Last Modified: 9/2/2014
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