JB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Marr, A. G.
Right arrow Articles by Squires, C. L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Marr, A. G.
Right arrow Articles by Squires, C. L.

 Previous Article  |  Next Article 

J Bacteriol. 1964 February; 87(2): 356-362
Copyright © 1964 by the American Society for Microbiology. All Rights Reserved.

EFFECT OF THE TEMPERATURE OF GROWTH OF ESCHERICHIA COLI ON THE FORMATION OF ß-GALACTOSIDASE

Allen G. Marr, John L. Ingraham and Craig L. Squires

Department of Bacteriology, University of California, Davis, California

ABSTRACT

MARR, ALLEN G. (University of California, Davis), JOHN L. INGRAHAM, AND CRAIG L. SQUIRES. Effect of the temperature of growth of Escherichia coli on the formation of ß-galactosidase. J. Bacteriol. 87:356–362. 1964.—The synthesis of ß-galactosidase was measured during exponential growth of Escherichia coli in a succinate-minimal medium over a temperature range of 10 to 43 C for the following: (i) a constitutive strain, and (ii) an inducible cryptic strain, induced maximally with isopropyl-thio-ß-D-galactopyranoside (IPTG), or induced submaximally with IPTG. The differential rates of synthesis of ß-galactosidase were identical for the constitutive strain and for the fully induced strain; the rates were constant from 20 to 43 C, and decreased progressively with a decrease in temperature below 20 C. Thus, in the absence of specific repression, the ability of E. coli to produce ß-galactosidase decreases at low temperature. The differential rate of the submaximally induced culture was minimal between 20 and 30 C, and increased progressively with temperature both above 30 C and below 20 C. That the repressor concentration is maximal at 20 C was established by measuring the rate of induced synthesis of ß-galactosidase as a function of the concentration of IPTG; the relative concentrations of repressor were 1.00:3.28:0.25 at 40, 20, and 10 C, respectively. After an abrupt change in temperature, the differential rate of a submaximally induced culture changed gradually to the rate of the steady state, which is in agreement with the proposal that the effect of temperature is on the concentration of repressor and not on the equilibrium between repressor and its site of action. The effect of temperature on catabolic repression was determined by comparing the differential rate of synthesis of ß-galactosidase by a constitutive strain grown in succinate-minimal medium with the rate in glucose-minimal medium at various temperatures; the ratio of the rates in the two media decreased progressively and approached 2.0 as the temperature of growth was increased.


J Bacteriol. 1964 February; 87(2): 356-362
Copyright © 1964 by the American Society for Microbiology. All Rights Reserved.




This article has been cited by other articles:




Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Appl. Environ. Microbiol. Infect. Immun. Eukaryot. Cell
Mol. Cell. Biol. J. Virol. Microbiol. Mol. Biol. Rev.
ALL ASM JOURNALS

Copyright © 1964 by the American Society for Microbiology. All rights reserved.