Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Futile cycling of ammonium ions via the high affinity potassium uptake system (Kdp) of Escherichia coli

Futile cycling of ammonium ions via the high affinity potassium uptake system (Kdp) of... 203 155 155 4 4 Ed T. Buurman M. Joost Teixeira de Mattos Oense M. Neijssel Department of Microbiology, Biotechnology Centre University of Amsterdam P.O. Box 20245 1000 HE Amsterdam The Netherlands Abstract Escherichia coli Frag1 was grown under various nutrient limitations in chemostat culture at a fixed temperature, dilution rate and pH both in the presence and the absence of a high concentration of ammonium ions by using either ammonium chloride or dl -alanine as the sole nitrogen source. The presence of high concentrations of ammonium ions in the extracellular fluids of potassium-limited cultures of E. coli Frag1 caused an increase of the specific rate of oxygen consumption of these cultures. In contrast, under phosphate-, sulphate- or magnesium-limited growth conditions no such increase could be observed. The presence of high concentrations of ammonium ions in potassium-limited cultures of E. coli Frag5, a mutant strain of E. coli Frag1 which lacks the high affinity potassium uptake system (Kdp), did not increase the specific rate of oxygen consumption. These results indicate that ammonium ions, very similar to potassium ions both in charge and size, are transported via the K dp leading to a futile cycle of ammonium ions and ammonia molecules (plus protons) across the cytoplasmic membrane. Both the uptake of ammonium ions and the extrusion of protons would increase the energy requirement of the cells and therefore increase their specific rate of oxygen consumption. The involvement of a (methyl)ammonium transport system in this futile cycle could be excluded. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Archives of Microbiology Springer Journals

Futile cycling of ammonium ions via the high affinity potassium uptake system (Kdp) of Escherichia coli

Loading next page...
 
/lp/springer-journals/futile-cycling-of-ammonium-ions-via-the-high-affinity-potassium-uptake-QiylLPxzsp

References (30)

Publisher
Springer Journals
Copyright
Copyright © 1991 by Springer-Verlag
Subject
Life Sciences; Biotechnology; Biochemistry, general; Cell Biology; Ecology; Microbial Ecology; Microbiology
ISSN
0302-8933
eISSN
1432-072X
DOI
10.1007/BF00243460
Publisher site
See Article on Publisher Site

Abstract

203 155 155 4 4 Ed T. Buurman M. Joost Teixeira de Mattos Oense M. Neijssel Department of Microbiology, Biotechnology Centre University of Amsterdam P.O. Box 20245 1000 HE Amsterdam The Netherlands Abstract Escherichia coli Frag1 was grown under various nutrient limitations in chemostat culture at a fixed temperature, dilution rate and pH both in the presence and the absence of a high concentration of ammonium ions by using either ammonium chloride or dl -alanine as the sole nitrogen source. The presence of high concentrations of ammonium ions in the extracellular fluids of potassium-limited cultures of E. coli Frag1 caused an increase of the specific rate of oxygen consumption of these cultures. In contrast, under phosphate-, sulphate- or magnesium-limited growth conditions no such increase could be observed. The presence of high concentrations of ammonium ions in potassium-limited cultures of E. coli Frag5, a mutant strain of E. coli Frag1 which lacks the high affinity potassium uptake system (Kdp), did not increase the specific rate of oxygen consumption. These results indicate that ammonium ions, very similar to potassium ions both in charge and size, are transported via the K dp leading to a futile cycle of ammonium ions and ammonia molecules (plus protons) across the cytoplasmic membrane. Both the uptake of ammonium ions and the extrusion of protons would increase the energy requirement of the cells and therefore increase their specific rate of oxygen consumption. The involvement of a (methyl)ammonium transport system in this futile cycle could be excluded.

Journal

Archives of MicrobiologySpringer Journals

Published: Mar 1, 1991

There are no references for this article.