Formation, Location, and Regulation of Endo-1,4-beta-Glucanases and beta-Glucosidases from Cellulomonas uda.
The formation and location of endo-1,4-beta-glucanases and beta-glucosidases were studied in cultures of Cellulomonas uda grown on microcrystalline cellulose, carboxymethyl cellulose, printed newspaper, and some mono- or disaccharides. Endo-1,4-Glucanases were found to be extracellular, but a very small amount of cell-bound endo-1,4-beta-glucanase was considered to be the basal endoglucanase level of the cells. The formation of extracellular endo-1,4-beta-glucanases was induced by cellobiose and repressed by glucose. Extracellular endoglucanase activity was inhibited by cellobiose but not by glucose. beta-Glucosidases, on the other hand, were formed constitutively and found to be cell bound. beta-Glucosidase activity was inhibited noncompetitively by glucose. Some characteristics such as the optimal pH for and the thermostability of the endoglucanases and beta-glucosidases and the end products of cellulose degradation were determined.
Stoppok
W
W
Gesellschaft für Biotechnologische Forschung mbH and Lehrstuhl für Biochemie and Biotechnologie der Universität Braunschweig, D-3300 Braunschweig, Federal Republic of Germany.
Rapp
P
P
Wagner
F
F