Separation and characterization of two extracelluar H₂O₂‐dependent oxidases from ligninolytic cultures of <i>Phanerochaete chrysosporium</i>

Abstract

Two H 2 O 2 ‐dependent oxidases found in the extracellular medium of the white rot fungus Phanerochaete chrysosporium were separated by chromatography on blue agarose. The first enzyme fraction to elute from the column generated ethylene from 2‐keto‐4‐thiomethylbutyric acid (KTBA) in the presence of veratryl alcohol, and catalyzed the α,β cleavage of the diarylpropane 1‐(3,4‐diethoxyphenyl)1,3‐dihdyroxy‐(4‐methoxyphenyl)propane (I). During the diarylpropane cleavage, 18 O from 18 O 2 was incorporated specifically into the α‐position of the product 1‐(4‐methoxyphenyl)1,2‐dihdyroxyethane (III), suggesting that this enzyme is an H 2 O 2 ‐dependent oxygenase. The second enzyme which binds to blue agarose is an Mn 2+ ‐dependent, lactate‐activated peroxidase. The enzyme catalyzed the oxidation of phenol red, o ‐dianisidine, Poly R, and a variety of other dyes. It was also capable of decarboxylating vanillic acid.