PHYSIOLOGY OF EXOLACCASE PRODUCTION BY THELEPHORA-TERRESTRIS

Thelephora terrestris, an ectomycorrhizal hymenomycete, produces extra cellular laccase when grown in minimal liquid medium. The enzyme was c haracterized as a protein of 66 kDa. The optimal pH varied depending o n the substrate utilized, being 5.0 for syringaldazine, 4.8 for guaiac ol and 3.4 for ABTS. The K-m was 2.52 +/- 0.4 mu M for syringaldazine, 16 +/- 1.9 mu M for ABTS and 120.6 +/- 4.9 mu M for guaiacol. The sec retion of laccase was biomass-dependent and independent of the glucose concentration in the medium. The addition of inducers did not increas e laccase production which was dependent upon the ammonium phosphate c oncentration. (C) 1998 Published by Elsevier Science B.V.