2007 Research Highlights
Research Area:
Strategic Goal: 1
SPA: Fire
Understanding wood decay mechanisms of Gloeophylum trabeum and Daldinia concentrica
using high-resolution solution-state NMR spectroscopy. Problem Area 1
Key Contacts: Daniel Yelle dyelle@fs.fed.us
Partners:
US ARS Dairy Forage Research Center, Madison, WI, and
Department of Bacteriology at the University of Wisconsin, Madison.
The brown-rot fungus, Gloeophyllum trabeum, is known to metabolize cellulose and also modify lignin structures in gymnosperms through demethoxylation. Finely ground cell wall material from Picea glauca (white spruce) dissolves in a solvent system containing dimethylsulfoxide and 1-methylimidazole in a ratio of 2:1 (v/v), keeping cell wall component structures intact. In situ acetylation of the spruce cell walls allow solution-state characterization via 2D nuclear magnetic resonance (NMR) experiments using gradient-HSQC 1-bond 13C- 1H correlation. Methoxyl and Derivatization Followed by Reductive Cleavage (DFRC) analyses of spruce, which underwent 50-70% wt. loss, not only displayed approximately 1/3 decrease in methoxyl content, but also substantial b-aryl ether cleavage, proving that the spruce lignin was highly degraded by the fungus through Fenton chemistry in a non-selective oxidation by hydroxyl-radicals.
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