Production of induced laccase by the fungus Rhizoctonia praticola

Abstract

The ability of the fungus Rhizoctonia praticola to produce an induced extracellular laccase was examined. Potential inducers, including substituted phenols, anilines, and benzoic acids, were added at a concentration of 1 mM to the growth media of fungal cultures. Of the 11 compounds tested, 5 were found to have an inductive effect. The most effective inducer, p-anisidine (p-methoxyaniline), stimulated laccase production by a factor of 30. Other parameters which influenced the production of laccase were temperature, condition of the mycelia at the time of the induction, and the concentration of the inducer. A comparison of the p-anisidine induced laccase with the constitutive laccase showed noticeable similarities in Km, pH optimum, and mobility in gel electrophoresis, suggesting that the two enzymes may be similar.