Hydrolytic efficiency of Penicillium occitanis cellulase: kinetic aspects

The parameters controlling the activity of the hyper-cellulolytic mutant Pol 6 of Penicillium occitanis cellulase were studied with regard to its efficiency for the hydrolysis of esparto grass cellulose. The optimal operational hydrolysis parameters were pH 5.0, temperature 45-55 degrees C and 32 enzyme units/g of substrate. The maximum conversion ratio to reducing sugars was 84%. The cellulase was thermally quite stable, its activity decreasing by 20% when held at 50 degrees C for 48 h. The cellulase was subject to end-product inhibition, with filter paper activity decreasing by 30% in the presence of 5% glucose. The results generally indicate the high efficiency of P. occitanis cellulase. It compares well with that from other microorganisms such as Trichoderma reesei.