Enzymatic properties of cellobiohydrolase immobilized in soil
1988
Chung, J.K. | Yang, Y.K. | Maeng, J.S. | Rhee, Y.H. (Chungnam National Univ., Taejon (Korea R.). Coll. of Natural Sciences)
The enzymatic properties of soil cellobiohydrolase were examined and compared with those of cellobiohydrolase-active extracts from soil in the forms of enzyme-humic complex and humic-free enzyme, and cellobiohydrolase partially purified from Aspergillus niger. The pH optima of soil cellobiohydrolase and cellobiohydrolase-humic complex were greater by 1.5-3.0 pH units than those of cellobiohydrolase in humic-free extract and from A. niger. Soil cellobiohydrolase and cellobiohydrolase-humic complex were remarkably resistant to thermal denaturation and proteolysis. These results confirm that cellobiohydrolase in soil is stable in conditions which rapidly inactivate microbial cellobiohydrolase and that its stability is due to the immobilization of this enzyme by association with humic substances. The Michaelis-Menten constants (Km) for soil, cellobiohydrolase-humic complex, humic-free extract and cellobiohydrolase from A. niger were 22.1 mg/m/, 11.3 mg/ m/, 10.6 mg/ml and 4.5 mg/ml of Avicel, respectively
显示更多 [+] 显示较少 [-]