LIGNOCELLULOLYTIC ENZYME PROFILES OF EDIBLE MUSHROOM FUNGI

One of the most economically-viable processes for the bioconversion of many types of lignocellulosic wastes is represented by edible mushroo m cultivation, Lentinula edodes, Volvariella volvacera and Pleurotus s ajor-caju are three important commercially cultivated mushrooms which exhibit varying abilities to utilise different lignocellulosics as gro wth substrate, Examination of the lignocellulolytic enzyme profiles of the three species show this diversity to be reflected in qualitative variations in the major enzymic determinants (i.e. cellulases, lignina ses) required for substrate bioconversion. For example, I., edodes, wh ich is cultivated on highly lignified substrates such as wood or sawdu st, produces two extracellular enzymes which have been associated with lignin depolymerisation in other fungi, (manganese peroxidase and lac case). Conversely, V. volvacea, which prefers high cellulose-, low lig nin-containing substrates produces a family of cellulolytic enzymes in cluding at least five endoglucanases, five cellobiohydrolases and two beta-glucosidases, but none of the recognised lignin-degrading enzymes .