How Does Wood Decay Start?
Oxidative cleavage of lignin, a wood biopolymer, is the first step in rotting wood. These fungi secrete several oxidative enzymes, but the relative importance of these agents in decay remains unclear. One new approach to this problem is to infer properties of these oxidants from how far they are from the fungus. Forest Service scientists grew the fungus Phanerochaete chrysosporium on wood sections with oxidant-sensing beads, which change from red to green with oxidation. The beads, having fixed locations relative to the fungal hyphae, enabled them to map the amount of oxidant as it spread out from the fungus. Data analysis using a mathematical reaction-diffusion model indicated that the dominant oxidant during early white rot had a half-life under 0.1 second. The best available hypothesis is that this oxidant is the cation radical of the secreted P. chrysosporium metabolite veratryl alcohol.
Forest Service Partners