Lignocellulosic polysaccharides and lignin degradation by wood decay fungi: the relevance of nonenzymatic Fenton-based reactions

Author(s)

Arantes, Valdeir ^[1] ; Milagres, Adriane M. F. ^[2] ; Filley, Timothy R. ^[3] ; Goodell, Barry ^[4]

Affiliation

^[1] Univ British Columbia, Fac Forestry, Dept Wood Sci, Forestry Prod Biotechnol Bioenergy Grp, Vancouver, BC V6T 1Z4 - Canada

^[2] Univ Sao Paulo, Escola Engn Lorena, Dept Biotechnol, Lorea, SP - Brazil

^[3] Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN 47907 - USA

^[4] Univ Maine, Sustainable Biomat & Bioenergy SFR Wood Sci, Orono, ME - USA

• Document type: Journal article
• Source: Journal of Industrial Microbiology & Biotechnology; v. 38, n. 4, p. 541-555, APR 2011.
• Web of Science Citations: 76

Abstract

The brown rot fungus Wolfiporia cocos and the selective white rot fungus Perenniporia medulla-panis produce peptides and phenolate-derivative compounds as low molecular weight Fe(3+)-reductants. Phenolates were the major compounds with Fe(3+)-reducing activity in both fungi and displayed Fe(3+)-reducing activity at pH 2.0 and 4.5 in the absence and presence of oxalic acid. The chemical structures of these compounds were identified. Together with Fe(3+) and H(2)O(2) (mediated Fenton reaction) they produced oxygen radicals that oxidized lignocellulosic polysaccharides and lignin extensively in vitro under conditions similar to those found in vivo. These results indicate that, in addition to the extensively studied Gloeophyllum trabeum-a model brown rot fungus-other brown rot fungi as well as selective white rot fungi, possess the means to promote Fenton chemistry to degrade cellulose and hemicellulose, and to modify lignin. Moreover, new information is provided, particularly regarding how lignin is attacked, and either repolymerized or solubilized depending on the type of fungal attack, and suggests a new pathway for selective white rot degradation of wood. The importance of Fenton reactions mediated by phenolates operating separately or synergistically with carbohydrate-degrading enzymes in brown rot fungi, and lignin-modifying enzymes in white rot fungi is discussed. This research improves our understanding of natural processes in carbon cycling in the environment, which may enable the exploration of novel methods for bioconversion of lignocellulose in the production of biofuels or polymers, in addition to the development of new and better ways to protect wood from degradation by microorganisms. (AU)

• FAPESP's process: 07/00993-9 - Production of enzymes and chelants by basidiomycetes and the relationship with the degradation of recalcitrant compounds
• Grantee: Adriane Maria Ferreira Milagres
• Support Opportunities: Regular Research Grants