ABSTRACT
Lignin is a plant cell wall, phenylpropanoid polymer synthesized by the free radical condensation of phenolic precursors, resulting in a hetero geneous, random, and highly branched structure [1,2], The unique structure of lignin requires depolymerization by extracellular, oxidative mechanisms, explaining its recalcitrance to degradation by most micro organisms [3-5]. Indeed, white-rot basidiomycetous fungi are the only known organisms that are capable of degrading lignin extensively to C 02 and H20 in axenic culture [4,5]. Early work indicated that lignin degradation by the best studied lignin-degrading fungus, Phanerochaete chrysosporium, is both oxidative and nonspecific [4-6]. T.ignin degradation by several white-rot fungi is strongly dependent on the presence of Mn in culture [7,8] and M n02 precipitates accumulate in wood during decay by many white-rot fungi [9].
