The overall objective of this project is to characterize the biochemical function of two enzymes, a lignin peroxidase (LiP) and a manganese peroxidase (MnP), in the oxidative degradation of lignin by the white-rot fungus Phanerochaete chrysosporium. Kinetic, spectroscopic and reactivity experiments will be conducted to ascertain the role of veratryl alcohol in the mechanism and regulation of LiP. Steady-state kinetic measurements, EPR, and resonance Raman spectroscopy will be used to characterize the active center of MnP and the role of Mn as redox couple in the enzyme. Lignin is the second most abundant biopolymer and the most abundant natural aromatic material on earth. An understanding of the role of these enzymes in the biodegradation of lignin may lead to the development of many useful biotechnological applications such as those in the pulp-paper and chemical industries. They would be less energy demanindg and more environmentally benign than existing processes.