Regulation of invertase in Aspergillus nidulans: effect of different carbon sources

• Published in: Journal of general microbiology Vol. 137; no. 2; pp. 315 - 321
• Main Authors: Vainstein, M.H, Peberdy, J.F
• Format: Journal Article
• Language: English
• Published: London Soc General Microbiol 01.02.1991; New York, NY Cambridge University Press
• Subjects: Aspergillus nidulans - enzymology; Aspergillus nidulans - growth & development; Aspergillus nidulellus; beta-Fructofuranosidase; Biological and medical sciences; Biotechnology; Carbohydrates - pharmacology; Culture Media; enzyme activity; Enzyme Induction; Enzyme Repression; fructose; Fructose - pharmacology; Fundamental and applied biological sciences. Psychology; glucose; Glucose - pharmacology; Glycoside Hydrolases - biosynthesis; growth; Growth, nutrition, metabolism, transports, enzymes. Molecular biology; Microbiology; mycelium; Mycology; raffinose; secretion; substrates; sucrose; Sucrose - pharmacology; synthesis; xylose; Xylose - pharmacology; Sucrose; Enzyme; Induction; β-D-Fructofuranosidase; Biosynthesis; Repression; Raffinose; Fungi; Substrate; Regulation(control); Aspergillus nidulans; Carbohydrate; Fungi Imperfecti; Kinetics; Thallophyta
• ISSN: 0022-1287; 1350-0872; 1465-2080
• DOI: 10.1099/00221287-137-2-315

Department of Botany, Microbial Biochemistry and Genetics Group, University of Nottingham, Nottingham NG7 2RD, UK ABSTRACT SUMMARY: Aspergillus nidulans produces an extracellular β-D-fructofuranoside fructohydrolase (invertase) when grown on a medium containing the β-fructofuranosides sucrose or raffinose, indicating that synthesis is subject to induction by the substrate. On a growth medium containing sucrose, production was maximal at 15 h in cultures incubated at 28 C°. After this time the level of detectable invertase in the cultures declined. A proportion of the enzyme was secreted during the linear growth phase of the fungus. Various sugars were investigated for induction of invertase, but only the two β-fructofuranosides induced high production levels; with the other sugars, the enzyme was produced only at a low constitutive level. Mycelium grown under repressive conditions (1% glucose), rapidly produced invertase when transferred to sucrose-containing medium. After 80 min the invertase level in these cultures was 26-fold higher than the constitutive level. The repressive effect of other sugars, e.g. glucose and xylose, on invertase production was also demonstrated in this experimental system. Present address: Laboratorio de Microbiologia, Departamento de Biologia Celular, Universidade de Brasilia, Brasilia, DF, Brazil.