Abstract
The addition of lactate to lightly buffered suspensions of resting cells of Escherichia coli caused an increase in the pH of the extracellular phase as lactate and protons entered the cell together. From the magnitude of the pH change and the non-electrogenic character of lactate uptake, we concluded that the stoichiometry of the process was 1 proton/lactate anion. The addition of alanine caused a slow increase in pH, also apparently due to the transport of the amino acid by a symport mechanism with 1 proton/alanine stoichiometry. When cells were grown in the chemostat with alanine as sole carbon source and as limiting nutrient, this stoichiometry was found to alter to 2 protons/alanine, and then to 4 protons/alanine. These increases stoichiometries were due to the selection of mutants. The consequences of these changes on the potential uptake capacity of the cells are discussed.
Full text
PDF












Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Berger E. A., Heppel L. A. Different mechanisms of energy coupling for the shock-sensitive and shock-resistant amino acid permeases of Escherichia coli. J Biol Chem. 1974 Dec 25;249(24):7747–7755. [PubMed] [Google Scholar]
- Cockburn M., Earnshaw P., Eddy A. A. The stoicheiometry of the absorption of protons with phosphate and L-glutamate by yeasts of the genus Saccharomyces. Biochem J. 1975 Mar;146(3):705–712. doi: 10.1042/bj1460705. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Collins S. H., Hamilton W. A. Magnitude of the protonmotive force in respiring Staphylococcus aureus and Escherichia coli. J Bacteriol. 1976 Jun;126(3):1224–1231. doi: 10.1128/jb.126.3.1224-1231.1976. [DOI] [PMC free article] [PubMed] [Google Scholar]
- DAVIS B. D., MINGIOLI E. S. Mutants of Escherichia coli requiring methionine or vitamin B12. J Bacteriol. 1950 Jul;60(1):17–28. doi: 10.1128/jb.60.1.17-28.1950. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Harold F. M. Conservation and transformation of energy by bacterial membranes. Bacteriol Rev. 1972 Jun;36(2):172–230. doi: 10.1128/br.36.2.172-230.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Harold F. M., Levin E. Lactic acid translocation: terminal step in glycolysis by Streptococcus faecalis. J Bacteriol. 1974 Mar;117(3):1141–1148. doi: 10.1128/jb.117.3.1141-1148.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Harold F. M., Spitz E. Accumulation of arsenate, phosphate, and aspartate by Sreptococcus faecalis. J Bacteriol. 1975 Apr;122(1):266–277. doi: 10.1128/jb.122.1.266-277.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lo T. C., Rayman M. K., Sanwal B. D. Transport of succinate in Escherichia coli. I. Biochemical and genetic studies of transport in whole cells. J Biol Chem. 1972 Oct 10;247(19):6323–6331. [PubMed] [Google Scholar]
- MAGER J., MAGASANIK B. Guanosine 5'-phosphate reductase and its role in the interconversion of purine nucleotides. J Biol Chem. 1960 May;235:1474–1478. [PubMed] [Google Scholar]
- Matin A., Konings W. N. Transport of lactate and succinate by membrane vesicles of Escherichia coli, Bacillus subtilis and a pseudomonas species. Eur J Biochem. 1973 Apr 2;34(1):58–67. doi: 10.1111/j.1432-1033.1973.tb02728.x. [DOI] [PubMed] [Google Scholar]
- Mitchell P. Chemiosmotic coupling in oxidative and photosynthetic phosphorylation. Biol Rev Camb Philos Soc. 1966 Aug;41(3):445–502. doi: 10.1111/j.1469-185x.1966.tb01501.x. [DOI] [PubMed] [Google Scholar]
- Mitchell P. Performance and conservation of osmotic work by proton-coupled solute porter systems. J Bioenerg. 1973 Jan;4(1):63–91. doi: 10.1007/BF01516051. [DOI] [PubMed] [Google Scholar]
- Niven D. F., Hamilton W. A. Mechanisms of energy coupling to the transport of amino acids by Staphylococcus aureus. Eur J Biochem. 1974 May 15;44(2):517–522. doi: 10.1111/j.1432-1033.1974.tb03510.x. [DOI] [PubMed] [Google Scholar]
- Niven D. F., Hamilton W. A. Valinomycin-induced amino acid uptake by Staphylococcus aureus. FEBS Lett. 1973 Dec 1;37(2):244–248. doi: 10.1016/0014-5793(73)80470-3. [DOI] [PubMed] [Google Scholar]
- Rahmanian M., Claus D. R., Oxender D. L. Multiplicity of leucine transport systems in Escherichia coli K-12. J Bacteriol. 1973 Dec;116(3):1258–1266. doi: 10.1128/jb.116.3.1258-1266.1973. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Robbins J. C., Oxender D. L. Transport systems for alanine, serine, and glycine in Escherichia coli K-12. J Bacteriol. 1973 Oct;116(1):12–18. doi: 10.1128/jb.116.1.12-18.1973. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Scholes P., Mitchell P. Acid-base titration across the plasma membrane of Micrococcus denitrificans: factors affecting the effective proton conductance and the respiratory rate. J Bioenerg. 1970 Jun;1(1):61–72. doi: 10.1007/BF01516089. [DOI] [PubMed] [Google Scholar]
- West I. C. Lactose transport coupled to proton movements in Escherichia coli. Biochem Biophys Res Commun. 1970 Nov 9;41(3):655–661. doi: 10.1016/0006-291x(70)90063-x. [DOI] [PubMed] [Google Scholar]
- West I. C., Mitchell P. Stoicheiometry of lactose-H+ symport across the plasma membrane of Escherichia coli. Biochem J. 1973 Mar;132(3):587–592. doi: 10.1042/bj1320587. [DOI] [PMC free article] [PubMed] [Google Scholar]
- West I., Mitchell P. Proton-coupled beta-galactoside translocation in non-metabolizing Escherichia coli. J Bioenerg. 1972 Aug;3(5):445–462. doi: 10.1007/BF01516082. [DOI] [PubMed] [Google Scholar]
- Winkler H. H., Wilson T. H. The role of energy coupling in the transport of beta-galactosides by Escherichia coli. J Biol Chem. 1966 May 25;241(10):2200–2211. [PubMed] [Google Scholar]