2,4-Dichlorophenol degradation using Streptomyces viridosporus T7A lignin peroxidase

The Streptomyces viridosporus T7A bacterium produces the extracellular lignin peroxidase ALiP-P3. The ALiP-P3-catalyzed oxidation of 2,4-dichlorophenol (DCP) was examined to understand its kinetic behavior. Initial rate data of the oxidation of DCP were obtained by a spectrophotometric peroxidase assay, and the kinetics were best modeled with a random-binding bireactant system, which differs from the ping-pong bireactant system that is typically used for horseradish peroxidase and lignin peroxidase from the fungus Phanerochaete chrysosporium, and suggests that either DCP or H2O2 may bind first to ALiP-P3. Chloride ion measurements indicate that 16% of the reacted DCP was fully dechlorinated by ALiP-P3. Chemical ionization mass spectrometry was also utilized to identify the DCP degradation product as a hydrophobic chlorinated dimer of mass 322.