Induction and preliminary characterization of intracellular beta-glucosidases from a cellulolytic Streptomyces strain.
The cellulolytic actinomycete Streptomyces sp. QM-B814 possess an intracellular beta-glucosidase system which is induced by cellobiose and carboxymethylcellulose. Maximal beta-glucosidase activity was attained 8-10 h after inducer addition to exponential phase growing cultures. The induction is depressed in the presence of glucose. The system is composed of two electrophoretically different beta-glucosidases forms showing relative molecular masses of about 60 and 35 kDa, and pI values in the range 4.2-4.5. Both beta-glucosidases are synthesized de novo. The enzymes share substrate preference and are both inhibited by delta-gluconolactone and p-chloromercuribenzoate. The induction pattern and glucose inhibition are similar for both enzymes.
Pérez-Pons
J A
JA
Dept. de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Spain.
Rebordosa
X
X
Querol
E
E
D002475:Cellobiose / Q000494:pharmacology; D002482:Cellulose / Q000378:metabolism*; D004790:Enzyme Induction; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D005947:Glucose / Q000494:pharmacology; D013302:Streptomyces / Q000187:drug effects / Q000201:enzymology*; D001617:beta-Glucosidase / Q000096:biosynthesis* / Q000302:isolation & purification
D002475:Cellobiose; D002482:Cellulose; D001617:beta-Glucosidase; D005947:Glucose