AEM
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 Lendenmann, U.
Right arrow Articles by Egli, T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Lendenmann, U.
Right arrow Articles by Egli, T.
Agricola
Right arrow Articles by Lendenmann, U.
Right arrow Articles by Egli, T.

Next Article 

Appl. Environ. Microbiol., May 1996, 1493-1499, Vol 62, No. 5
Copyright © 1996, American Society for Microbiology

Kinetics of the simultaneous utilization of sugar mixtures by Escherichia coli in continuous culture

U Lendenmann, M Snozzi and T Egli
Swiss Federal Institute for Environmental Science and Technology (EAWAG), Swiss Federal Institute of Technology (ETH), Dubendorf, Switzerland.

In natural environments heterotrophic microorganisms encounter complex mixtures of carbon sources, each of which is present at a concentration of a few micrograms per liter or even less. Under such conditions no significant growth would be expected if cells utilized only one of the available carbon compounds, as suggested by the principle of diauxic growth. Indeed, there is much evidence that microbial cells utilize many carbon compounds simultaneously. Whereas the kinetics of single- substrate and diauxic growth are well understood, little is known about how microbial growth rates depend on the concentrations of several simultaneously utilized carbon sources. In this study this question was answered for carbon-limited chemostat growth of Escherichia coli fed with mixtures of up to six sugars; the sugars used were glucose, galactose, maltose, ribose, arabinose, and fructose. Independent of the mixture composition and dilution rate tested, E. coli utilized all sugars simultaneously. Compared with growth with a single sugar at a particular growth rate, the steady-state concentrations were consistently lower during simultaneous utilization of mixtures of sugars. The steady-state concentrations of particular sugars depended approximately linearly on their contributions to the total carbon consumption rate of the culture. Our experimental data demonstrate that the simultaneous utilization of mixtures of carbon sources enables heterotrophic microbes to grow relatively fast even in the presence of low environmental substrate concentrations. We propose that the observed reductions in the steady-state concentrations of individual carbon sources during simultaneous utilization of mixtures of carbon sources by heterotrophic microorganisms reflect a general kinetic principle.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. Microbiol. Mol. Biol. Rev. Eukaryot. Cell All ASM Journals

Copyright © 1996 by the American Society for Microbiology. All rights reserved.