Cometabolic degradation of o-cresol and 2,6-dimethylphenol by Penicillium frequentans Bi 7/2.

o-Cresol induced glucose-grown resting mycelia of Penicillium frequentans Bi 7/2 (ATCC-number: 96048) immediately oxidized o-cresol and other phenols. After precultivation on glucose and phenol degradation started after a lag-phase of 24 hours. Metabolites of o-cresol metabolism were methylhydroquinone, methyl-p-benzoquinone, 2-methyl-5-hydroxyhydroquinone and 2-methyl-5-hydroxy-p-benzoquinone. The initial reaction is probably catalyzed by a NADPH dependent hydroxylase which is specific for o-cresol. The metabolism of 2,6-dimethylphenol (2,6-xylenol) occurred via 2,6-dimethylhydroquinone, 2,6-dimethyl-p-benzoquinone, 2,6-dimethyl-3-hydroxyhydroquinone, 2,6-dimethyl-3-hydroxy-p-benzoquinone and 3-methyl-2-hydroxybenzoic acid.