Abstract
An ammonium transport system in the phototrophic N2-fixing bacteriumRhodospirillum rubrum was characterized by using the uptake of14C-methylamine as a probe.
Uptake showed saturation kinetics with an apparentK m =110 μM. It was competitively inhibited by ammonium (K i =7 μM). Uptake exhibited a narrow pH maximum around pH 7.0.
Up to 200-fold gradients across the membrane were formed within 40–60 min. Gradient formation was inhibited by carbon starvation, azide or cyanide. Pre-accumulated methylamine was released by ammonium pulses to more than 80%, indicating only minor metabolization.
The synthesis of the transport system was repressed by ammonium in high concentrations.
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References
Alef K, Arp DJ, Zumft WG (1981) Nitrogenase switch-off by ammonia inRhodopseudomonas palustris: Loss under nitrogen deficiency and independence from adenylation of glutamine synthetase. Arch Microbiol 130:138–142
Barnes E Jr, Zimniak P (1981) Transport of ammonium and methylammonium ions byAzotobacter vinelandii. J Bacteriol 146:512–516
Brill WJ (1981) Genetics of dinitrogen fixation. In: Bothe H, Trebst A (eds) Biology of inorganic nitrogen and sulfur. Springer, Berlin Heidelberg New York, pp 81–86
Hackette SL, Syke GE, Burton C, Segel IH (1970) Characterization of ammonium transport system in filamentous fungi with methylammonium-C14 as the substrate. J Biol Chem 245:4241–4250
Kleiner D (1981) The transport of NH3 and NH +4 across biological membranes. Biochim Biophys Acta 639:41–52
Kleiner D (1982) Ammonium (methylammonium) transport byKlebsielia pneumoniae. Biochim Biophys Acta (in press)
Kleiner D, Fitzke E (1979) Evidence for ammonia translocation byClostridium pasteurianum. Biochem Biophys Res Commun 86:211–217
Kleiner D, Fitzke E (1981) Some properties of a new electrogenic transport system: The ammonium (methylammonium) carrier fromClostridium pasteurianum. Biochim Biophys Acta 641:138–147
Ludden PW, Burris RH (1979) Removal of an adenine-like molecule during activation of dinitrogenase reductase fromRhodospirillum rubrum. Proc Natl Acad Sci USA 76:6201–6205
Miovic ML, Gibson J (1973) Nucleotide pools and adenylate energy charge in balanced and unbalanced growth ofChromatium. J Bacteriol 114:86–95
Nordlund S, Eriksson U, Baltscheffsky H (1977) Necessity of membrane component for nitrogenase activity inRhodospirillum rubrum. Biochim Biophys Acta 462:187–195
Pfennig N (1974)Rhodopseudomonas globiformis, sp. n., a new species of the Rhodospirillaceae. Arch Microbiol 100:197–206
Stevenson R, Silver S (1977) Methylammonium uptake byEscherichia coli: Evidence for a bacterial NH +4 transport system. Biochem Biophys Res Commun 75:1133–1139
Sweet WJ, Burris RH (1981) Inhibition of nitrogenase activity by NH +4 inRhodospirillum rubrum. J Bacteriol 145:824–831
Yoch D, Cantu M (1980) Changes in the regulatory form ofRhodospirillum rubrum nitrogenase as influenced by nutritional and environmental factors. J Bacteriol 142:899–907
Zumft WG, Alef K, Mümmler S (1981) Regulation of nitrogenase activity in Rhodospirillaceae. In: Gibson AH, Newton WE (es) Current perspectives in nitrogen fixation. Austral Acad Sci, Canberra, pp 190–193
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Alef, K., Kleiner, D. Evidence for an ammonium transport system in the N2-fixing phototrophic bacteriumRhodospirillum rubrum . Arch. Microbiol. 132, 79–81 (1982). https://doi.org/10.1007/BF00690822
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DOI: https://doi.org/10.1007/BF00690822