Evaluation of the hydrolytic potential of a crude cellulase from mixed cultivation of Trichoderma reesei and Aspergillus phoenicis

Abstract

Mixed cultivation of Trichoderma reesei Rut C30 and Aspergillus phoenicis produced a cellulase complex which showed enhanced activity against cellulose. Initial rates of glucose production were improved up to twofold over cellulase from Trichoderma alone. For the mixed culture cellulase, the pH optimum was found to be slightly different when measured on the basis of glucose production rate (4.5–4.75), than if measured on the basis of production of total reducing sugars (4.0–4.25). The initial rate of glucose and reducing sugar production increased with temperature over the range tested (40–60°C). Stability of individual enzyme component activities were tested at 50 and 60°C. β-Glucosidase (cellobiase or β- d-glucoside glucohydrolase, EC 3.2.1.21) activity was most labile at elevated temperatures ( t 1 2 = 10 h at 60°C and 48 h at 50°C). The mixed culture enzyme was more resistant to end product inhibition by glucose than the Trichoderma enzyme. Hydrolysis of steam exploded aspen wood (SEAW) by the mixed culture cellulase was markedly improved over that achieved by the Trichoderma cellulase.