FIG 9.

Lignin modifications and oxidation pathways by Termitomyces. (A) Schematic depiction of lignin oxidation by, e.g., laccases (Lac) in contrast to degradation by LiP and VP typically found in white-rot fungi (gray box); (B) oxidation and oxidative demethylation of lignin substructures by 2-MH₂Q-catalyzed Fenton chemistry via the formation of short-lived hydroxyl radicals and regeneration of H₂Q by (intracellular) benzoquinone reductases (QR); (C) formation of H₂O₂ by (aryl)-alcohol oxidases (AAO) and glyoxal oxidases (GLX); (D) oxidative C-C cleavage of lignin substructures via phenoxy and methoxy radicals derived from radicals and/or enzymatic processes.