Purification And Properties Of Cellulases From Humicola Insolens YH-8

The cultural mixture from Humicola insolens was smashed by ultrasonic crashing intrument and we can know that this cellulase is outside-cell enzymes. The enzyme indentified by polypropylene gel electrophoresis has more than 5 groups.The secreted cellulases from Humicola insolens is purified by means of 1.5 folds volume ethanol deposition, DEAE-Sephadex A-50 chromatography and DEAE-Sephadex G-100 chromatography. The purified cellulase showed a single band on SDS-polyacrylamide gel electrophoresis(PAGE).The molecular weights of the two enzyme are respectively about 55kD and 80 kD.The biocatalyzed characters of the purified cellulases were investigated with the CMC-Na as substrate. The most appropriate catalyzed temprature for cellulase 1 is 60 "C,and 65 for cellulase 2. The two enzymes have the extreme stability at the temperatures no more than 50.The CMC-Na has the protective effect on the cellulase. The pH stability range of cellulase 1 is 4 ~ 8, and 6-9 for cellulase 2. Zn2+, Ca2+, Mg2+, K+, Li+can ativate cellulase 1. K+, Li"1" can ativate cellulase 2. Cellulase 1 can mainly decompose CMC and salicin. Cellulase 2 can decompose not only CMC and salicin, but other substrates feebly.