Abstract: The crude cellulase of Trichoderma reesei was purified twice by ammonium sulfate fractionation, dialysis andSephadex G-100 gel filtration. The purified cellulase showed that the four distinct protein bands assayed by SDS-PAGE,showed molecular weights about 74,000、55,000、47,000、26,000, respectively. According to the molecular weight andconcentration, the four compositions were assayed as β-glucanase, CBHI, CBHII and EGI. The optimal degrading conditionsfor cellulase obtained were pH 5.0 and 50℃. The enzyme was stable between pH4.0 and 6.0, and at a temperature below 50℃.When innocubated at 70℃ for 30min, 90% of enzyme activity would be lost. When pH was beyond 8.0, almost all enzymeactivity would be lost. The enzyme activity was distinctively inhibited by metal ions such as Hg2+、Ag2+、Al3+、Pb2+ andFe3+, but enhanced by Mn2+、Co2+、Fe2+、Zn2+ and Ca2+, By Na+、Mg2+、Ba2+、Cu2+ and Ni2+ it had no significanteffect.

Key words: Trichoderma reesei, cellulase, purification, characteristics