ENZYMES AND SMALL MOLECULAR-MASS AGENTS INVOLVED WITH LIGNOCELLULOSE DEGRADATION

Electron microscopic and biochemical studies of lignocellulose degradation by wood-rotting fungi have shown that enzymes such as lignin peroxidases, manganese-dependent peroxidases, laccases and cellulases are too large to penetrate undegraded secondary wood cell walls. Degradation occurs by surface interaction between cell wall and enzymes, but initiation of decay at a distance from the fungal hyphae must involve diffusible low-molecular mass agents. The roles of hydrogen peroxide, veratryl alcohol, oxalate, Fe2+-Fe3+ and Mn2+-Mn3+, as such agents in lignocellulose degradation are discussed.