Induction and preliminary characterization of intracellular β-glucosidases from a cellulolytic Streptomyces strain

• Published in: FEMS microbiology letters 1995-05, Vol.128 (3), p.235-239
• Main Authors: Pérez-pons, Josep A., Rebordosa, Xavier, Querol, Enrique
• Format: Article
• Language: English
• Subjects: Bacteriology; beta-Glucosidase - biosynthesis; beta-Glucosidase - isolation & purification; Biological and medical sciences; Biology of microorganisms of confirmed or potential industrial interest; Biotechnology; Cellobiose - pharmacology; Cellulolytic; Cellulose - metabolism; Enzyme Induction; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Bacterial; Gene Expression Regulation, Enzymologic; Glucose - pharmacology; Metabolism. Enzymes; Microbiology; Mission oriented research; Physiology and metabolism; Streptomyces; Streptomyces - drug effects; Streptomyces - enzymology; β-Glucosidase
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1016/0378-1097(95)00095-M

The cellulolytic actinomycete Streptomyces sp. QM-B814 posasses an intracellular β-glucosidase system which is induced by cellobiose and carboxymethylcellulose. Maximal β-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 β-glucosidase forms showing relative molecular masses of about 60 and 35 kDa, and p I values in the range 4.2–4.5. Both β-glucosidases are synthesized de novo. The enzymes share substrate preference and are both inhibited by δ-gluconolactone and p-chloromercuribenzoate. The induction pattern and glucose inhibition are similar for both enzymes.