High pressure enhancement of cellulase activities

High pressure application of 150MPa did not affect CMCase activity but enhanced P-glucosidase and Avicelase activities of a cellulase system secreted from Acremonium cellulolyticus (Yamanobe et al., Agric. Biol. Chem. 1987; 51: 65-74.) by 1.5 and 1.2 folds, respectively, at the optimum temperature under ambient pressure, 50degreesC. Addition of another cellulase system from Aspergillus niger made CMCase activity pressure sensitive, and the high pressure application doubled the activity of the mixture. The high pressure application did not enhanced filter papaer saccharifying (FPS) activity of Acremonium system in early stage of the reaction, but enhanced by 1.5 folds during prolonged reaction. With respect to the enzyme mixture, the high pressure application doubled this activity in the early stage, but the factor of the enhancement decreased to 1.5 folds later. These time courses suggested that the rate-determining activity of FPS is CMCase activity in the early stage, and turns to be P-glucosidase activity later. The high pressure application increased the optimum temperature of FPS reaction by the enzyme mixture by 15degreesC, and at 150MPa, the activity at 65degreesC was three times as high as that at 50degreesC. Therefore, the high pressure application enhanced FPS activity at the optimum temperature by 7.8 folds.