ENZYMES AND SMALL MOLECULAR-MASS AGENTS INVOLVED WITH LIGNOCELLULOSE DEGRADATION

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