Oxidation of phenolic pollutants by a lignin degrading enzyme from the white-rot fungus Phanerochaete chrysosporium

The wood rotting fungus Phanerochaete chrysosporium produces lignin degrading enzymes that have been implicated in pollutant degradation by the organism. One of these enzymes, ligninase, was studied to evaluate its application potential in industrial wastewater treatment. The enzyme was observed to catalyze the oxidation of several phenolic pollutants by hydrogen peroxide, although only partial removal of target compounds was observed in preliminary tests. A number of subsequent tests were conducted to improve target compound removal, using o-cresol as model substrate. Removal of o-cresol was enhanced by increasing enzyme concentration, by adding the co-catalyst veratryl alcohol (3,4-dimethoxybenzyl alcohol), or by controlling the rate of addition of hydrogen peroxide to batch reaction systems. Controlled addition of peroxide is proposed to minimize enzyme inactivation during reaction, thereby extending the useful life of the enzyme.