Lignolytic Enzymes of a MushroomStereum ostreaIsolated from Wood Logs

Abstract

Production of lignolytic enzymes by the mushroom fungusStereum ostreain liquid medium under conditions of vegetative growth was examined for 10 days in comparison to the reference culturePhanerochaete chrysosporium. Though growth and secretion of extracellular protein byS. ostreawere comparable to those ofP. chrysosporium, yields of laccase enzyme byS. ostreawere higher than laccase titres ofP. chrysosporiumby more than 2 folds on the peak production time interval (IVth day of incubation).S. ostreayielded titres of 25 units of laccase/ml as against 8.9 units of laccase/ml on the IVth day of incubation.Stereum ostreaalso exhibited activities of other lignolytic enzymes, lignin peroxidase (LiP) and manganese peroxidase (MnP), higher than the reference culture. Growth ofS. ostreaon the medium in the presence of Remazol orange 16 resulted in the decolourisation of dye, confirming the presence of lignolytic enzymes.S. ostreaappears to be a promising culture with complete lignolytic system.