COMPARATIVE-EVALUATION OF HYDROLYTIC EFFICIENCY TOWARD MICROCRYSTALLINE CELLULOSE OF PENICILLIUM AND TRICHODERMA CELLULASES

Composition, stability at different pH and temperatures and hydrolytic efficiency toward microcrystalline cellulose (MCC) of Penicillium cel lulase were evaluated. The pH optimum (4.5-5.0) of filter paper activi ty (FPA) and temperature optimum (50-55 degrees C) were determined. Ma ximum stability of FPA was observed at pH 4.0-5.0 and temperature 40-5 0 degrees C. A minor contribution of stirring (3-4%) in inactivation o f Penicillium preparation was shown. Kinetic parameters of MCC hydroly sis by Penicillium cellulase were determined at optimal conditions (pH 4.5, 50 degrees C): K-m=50 g/l, V-max=330 mu M/min per gram of protei n. More effective saccharification of MCC by Penicillium preparations compared to Trichoderma reesei cellulases with the same level of total cellulolytic activity (FPA=1.0 U/ml) was demonstrated. Glucose concen tration in 24 h hydrolysate was 41 g/l for Penicillium cellulase, 15 g /l for T. reesei (Privolzhski Fermentation Plant) and 26 g/l for T. re esei (Genencor). Hydrolysates of Penicillum cellulase contained only 9 % of cellobiose compared to 24-40% of cellobiose for T. reesei cellula ses. Factors contributing to superior properties of Penicillium cellul ase - higher level of cellobiase activity and higher operational stabi lity - are discussed.