Lack of lignin degradation by glucose oxidase-negative mutants of Phanerochaete chrysosporium.

Glucose oxidase-negative (gox-) mutants of Phanerochaete chrysosporium were isolated after exposing conidia to UV irradiation. The gox- mutants exhibited little or no ability to degrade lignin (2-[14C]-synthetic lignin to 14CO2); however, they retained other secondary metabolic features such as the ability to conidiate and produce veratryl alcohol, suggesting that they are not pleiotropic for secondary metabolism. Lignin degradation activity was restored in gox+ revertants. These results, in support of earlier evidence, indicate that glucose oxidase activity plays an important role in lignin degradation by P. chrysosporium.