EFFECT OF NUTRIENT NITROGEN AND MANGANESE ON MANGANESE PEROXIDASE ANDLACCASE PRODUCTION BY PLEUROTUS-SAJOR-CAJU

Pleurotus sajor-caju, strain Pl-27, produces manganese-dependent perox idase (MnP) and laccase, but not lignin peroxidase, when grown on a de fined medium with glucose as sole carbon source. MnP activity was dete cted in fungal cultures supplemented with both high (26 mM-N) and low (2.6 mM-N) nutrient nitrogen although higher specific activity values were recorded under the latter conditions. Conversely, laccase product ion was not influenced by nutrient nitrogen levels under the growth co nditions adopted. Both the titre and time of appearence of MnP were al so affected by the concentration of Mn in the culture medium with high est enzyme levels recorded in cultures supplemented with 15 ppm Mn. Tw o MnP and five laccase isoforms were identified by FPLC and gel electr ophoresis.