Abstract
1. I discuss the following aspects of Phanerochaete chrysosporium ligninase, the enzyme that has been shown to degrade a number of lignin-model compounds, and environmentally significant polycyclic aromatic hydrocarbons and polychlorinated phenols. 2. The primary mode of oxidation involves formation of a cation radical, which undergoes either hydrolysis or carbon—carbon bond cleavage. 3. In the presence of reducing substrate such as oxalic acid, ligninase has reductive activity that has been shown to be responsible for radical-mediated degradation of halogenated chemicals. 4. Electron spin resonance technique can be used to monitor the cation radical and other radical formation during ligninase-mediated degradation of lignin-model compounds and other chemicals.