The Effect of Exogenous Energy Sources on the Synthesis of ß-Galactosidase in Resting-Cell Suspensions of Escherichia coli
Open Access
- 31 October 1961
- journal article
- research article
- Published by Rockefeller University Press in The Journal of general physiology
- Vol. 45 (2), 229-241
- https://doi.org/10.1085/jgp.45.2.229
Abstract
Using methyl-l-thio-[beta]-D-galactoside as the inducer, the biosynthesis of [beta]-galactosidase was observed in Escherichia coli B with only endogenous sources of nitrogen and energy available. The addition of glucose, ribose, xylose, or glycerol as exogenous energy sources to nitrogen-deficient media blocked enzyme formation. Preinduction of the resting cells failed to overcome inhibition by the added energy sources. With limited quantities of glucose, ribose, xylose, or glycerol, synthesis of [beta]-galactosidase resumed abruptly and continued at the rate normal for cells in nitrogen-deficient media. Comparison of enzyme activities with oxygen uptake data revealed a reduction in the rate of oxygen uptake at the time enzyme synthesis resumed in media originally containing small amounts of energy sources. This change corresponded to only a fraction of the oxygen required for complete oxidation of one of the exogenous substrates. It is suggested that inhibition by these particular exogenous substrates involves metabolism to a common repressor or interference with an energy-transfer system.Keywords
This publication has 9 references indexed in Scilit:
- PHYSIOLOGY OF THE INHIBITION BY GLUCOSE OF THE INDUCED SYNTHESIS OF THE β-GALACTOSIDE-ENZYME SYSTEM OF ESCHERICHIA COLIJournal of Bacteriology, 1959
- SUR LEXPRESSION ET LE ROLE DES ALLELES INDUCTIBLE ET CONSTITUTIF DANS LA SYNTHESE DE LA BETA-GALACTOSIDASE CHEZ DES ZYGOTES DESCHERICHIA-COLI1958
- Nutrition of Bacteria and FungiAnnual Review of Microbiology, 1957
- EFFECT OF MIXTURES OF SUBSTRATES ON THE BIOSYNTHESIS OF INDUCIBLE ENZYMES IN AEROBACTER AEROGENESJournal of Bacteriology, 1957
- The Preferential Synthesis of -Galactosidase in Escherichia coliJournal of General Microbiology, 1955
- THE BETA- d -GALACTOSIDASE OF ESCHERICHIA COLI, STRAIN K-12Journal of Bacteriology, 1950