SUMMARY: The transport of glycine betaine by Staphylococcus aureus was investigated. Two transport systems were found that could be differentiated on the basis of their affinity for glycine betaine and their activation by osmotic pressure. The high-affinity system was relatively independent of osmotic pressure and exhibited a Km of approximately 3 μM. This system was not inhibited by proline, for which a separate high-affinity transport system has been recently discovered. The low-affinity system was activated approximately 35-fold by an increase in osmotic pressure and exhibited a Km of approximately 130 μM for glycine betaine. This system is partially inhibited by excess proline and may be identical to the low-affinity system recently described for proline. Both glycine betaine transport systems are Na+-dependent.
AndersonC. B. & WitterL. D. ( 1982;). Glutamine and proline accumulation by Staphylococcus aureus with reduction in water activity. . Applied and Environmental Microbiology43, 1501-1503.
BaeJ. -H. & MillerK. J. ( 1992;). Identification of two proline transport systems in Staphylococcus aureus and their possible role in osmoregulation. . Applied and Environmental Microbiology58, 471-475.
BoothI. R., CairneyJ., SutherlandL. & HigginsC. F. ( 1988;). Enteric bacteria and osmotic stress : an integrated homeostatic system.. Journal of Applied Bacteriology Symposium Supplement355-495.
CairneyJ. C., HigginsC. F. & BoothI. R. ( 1984;). Proline uptake through the major transport system (PP-I : putP) of Salmonella typhimurium is coupled to Na+ ions.. Journal of Bacteriology160, 22-27.
CairneyJ., BoothI. R. & HigginsC. F. ( 1985a;). Salmonella typhimurium proP gene encodes a transport system for the osmoprotectant glycine betaine. . Journal of Bacteriology164, 1218-1223.
CairneyJ., BoothI. R. & HigginsC. F. ( 1985b;). Osmoregulation of gene expression in Salmonella typhimurium: proU encodes an osmotically-induced glycine betaine transport system. . Journal of Bacteriology164, 1224-1232.
GrahamJ. E. & WilkinsonB. J. ( 1992;). Staphylococcus aureus osmoregulation: roles for choline, glycine betaine, proline and taurine. . Journal of Bacteriology174, 2711-2716.
KooS. -P., HigginsC. F. & BoothI. R. ( 1991;). Regulation of compatible solute accumulation in Salmonella typhimurium: evidence for a glycine betaine effiux system. . Journal of General Microbiology137, 2617-2625.
KoujimaI., HayashiH., TomochikaA., OkadaA. & KanemasaY. ( 1978;). Adaptational change in proline and water content of Staphylococcus aureus after alteration of environmental salt concentration. . Applied and Environmental Microbiology35, 467-470.
KuninC. M. & RudyJ. ( 1991;). Effect of NaCl-induced osmotic stress on intracellular concentrations of glycine betaine and potassium in Escherichia coli, Enterococcus faecalis and staphylococci. . Journal of Laboratory Clinical Medicine118, 217-224.
MillerK. J., ZeltS. C. & BaeJ. -H. ( 1991;). Glycine betaine and proline are the principal compatible solutes of Staphyloccus aureus. . Current Microbiology23, 131-137.
TownsendD. E. & Wilkin SonB. J. ( 1992;). Proline transport in Staphylococcus aureus: a high-affinity system and a low affinity system involved in osmoregulation. . Journal of Bacteriology174, 2702-2710.