Production and use of enzymes derived from the fungus Pleurotus ostreatus in the hydrolysis of sugarcane bagasse

White-rot fungi are able to degrade highly lignified substrates. This characteristic allows us to assume that these organisms possess a cellulolytic system with differentiated activity on lignin-rich substrates. This study evaluates how cellulolytic enzymes produced by the white-rot fungus Pleurotus ostreatus perform in the hydrolysis of alkaline sulphite pretreated sugarcane bagasse. The production of endoglucanases in submerged cultures of P.ostreatus was obtained in medium contained only sugarcane bagasse as carbon source. The reference hydrolysis experiments were performed with enzyme loadings of 10 FPU and 5 FPU from cellulases derived from Trichoderma reesei ATCC 26921 mixed with 15 UI of β-glucosidase from Aspergillus niger (enzyme loadings expressed in units per gram of pretreated bagasse). For the hydrolysis experiments that used enzymes from P. ostreatus, the enzyme loading was adjusted in order to replace 50% of original endoglucanase activity from T. reesei by enzymes from P. ostreatus. The addition of P. ostreatus enzymes caused a change in the overall levels of hydrolytic enzymes present in the reaction medium. The cellulose conversion during the hydrolysis showed that the enzymes from P. ostreatus provided initial hydrolysis rate values similar to those obtained in reference experiments. This result was achieved even with a cellobiohydrolase loading twice lower than in reference experiments, which led to the conclusion that the enzymes derived from P. ostreatus can show differentiated cellulolytic activity. However, the cellulose conversion after 8-24h hydrolysis supplemented with enzymes from P. ostreatus was slightly lower than that obtained with high loading of cellulases from T. reesei.