Hydrogen Peroxide and Iron: A Proposed System for Decomposition of Wood by Brown-rot Basidiomycetes

Jerome W. Koenigs

Abstract


Low concentrations of H2O2 and Fe++ caused rapid weight loss of wood of sweetgum and loblolly pine. The degree of polymerization of cellulose in treated woods decreased rapidly at low weight loss and then diminished gradually. The alkali solubility of exposed woods increased rapidly at low weight loss and was inversely related to the degree of polymerization. The H2O2-Fe system solubilized hemicelluloses of both woods more readily than cellulose. Lignin of sweetgum, but not pine, was changed so that it was solubilized by strong acid hydrolysis. The optimal pH for weight loss was about 3.3 for sweetgum and 3.0 for pine. Wood of both species absorbed much of the available Fe from solution.

The literature suggests that brown-rot is oxidative rather than being strictly hydrolytic. The H2O2-Fe++ system oxidizes cotton cellulose, and it essentially reproduced in wood and wood cellulose, characteristics of brown-rot basidiomycetes. These fungi produce H2O2 from native substrates in wood (Koenigs, 1974) and the optimal pH for degradation. Thus, it is proposed that these fungi may attack cellulose and partly decay wood via an H2O2-Fe++ system.


Keywords


Pinus taeda;Liquidambar styraciflua;wood decay;weight loss;cellulolysis;depolymerization;lignin solubility

Full Text:

PDF

Refbacks

  • There are currently no refbacks.