Abstract
Growth experiments in batch cultures indicated that the uptake of nitrate by the marine pseudomonad PL1 was inhibited in the presence of ammonia provided that the ammonia concentration was higher than 1 mM. At ammonia concentrations of less than about 1 mM, however, both nitrate and ammonia were utilised simultaneously. The saturation constants for nitrate and ammonia uptake were both 2.6x10-4 M, and similar to the Michaelis constants of nitrate reductase for nitrate (2.9x10-4 M) and glutamine synthetase for ammonia (2x10-4 M). Nitrate reductase activity linked to NADH was detected in chemostat-grown cultures with nitrate as nitrogen source, and in cultures containing limiting concentrations of nitrate and ammonia, ammonia or glutamate. Enzyme synthesis appeared to be repressed in cultures containing an excess of ammonia or glutamate. Chemostat cultures utilised ammonia or glutamate in preference to nitrate, while there was no marked preference between ammonia and glutamate.
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Literature Cited
Brown, C.M. and B. Johnson: Inorganic nitrogen assimilation in aquatic microorganisms. Adv. aquat. Microbiol. 1, (1975). (In press)
—, D.S. Macdonald-Brown and S.O.Stanley: Inorganic nitrogen assimilation in marine bacteria: nitrogen assimilation in some marine pseudomonads. J. mar. biol. Ass. U.K. 52, 793–804 (1972)
——— The mechanisms of nitrogen assimilation in pseudomonads. Antonie van Leeuwenhoek 39, 89–98 (1973)
— and S.O. Stanley: Environment-mediated changes in the cellular content of the “pool” constituents and their associated changes in cell physiology. J. appl. Chem. Biotechnol. 22, 363–389 (1972)
Eppley, R.W. and J.L. Coatsworth: Uptake of nitrate and nitrite by Ditylum brightwellii, kinetics and mechanisms. J. Phycol. 4, 151–156 (1968)
—— and L. Solorzano: Studies on nitrate reductase in marine phytoplankton. Limnol. Oceanogr. 14, 194–205 (1969a)
—, T.T. Packard and J.J. MacIsaac: Nitrate reductase in Peru Current phytoplankton. Mar. Biol. 6, 195–199 (1970)
—, J.N. Rogers and J.J. McCarthy: Half-saturation constants for uptake of nitrate and ammonium by marine phytoplankton. Limnol. Oceanogr. 14, 912–920 (1969b)
Fawcett, J.K. and J.E. Scott: A rapid and precise method for the determination of urea. J. clin. Path. 13, 156–160 (1960)
Guerrero, M.G., J.M. Vege, E. Leadbetter and M. Losada: Preparation and characterisation of a soluble nitrate reductase from Azotobacter chroococcum. Arch. Mikrobiol. 19, 287–304 (1973)
Harris, G. and R. Parsons: Nitrogenous constituents of brewing materials. XI. Nucleic acids of malt and their fate during brewing. J. Inst. Brew. 64, 308–314 (1958)
Lowry, O.H., M.R. Rosebrough, A.L. Farr and R.J. Randall: Protein measurement with the Folin phenol reagent. J. biol. Chem. 193, 265–275 (1951)
McCarthy, J.J. and R.W. Eppley: A comparison of chemical, isotopical and enzymatic methods for measuring nitrogen assimilation of marine phytoplankton. Limnol. Oceanogr. 17, 371–382 (1972)
Montgomery, H.A.C. and J.F. Dymock: The determination of nitrite in water. Analyst, Lond. 86, 414–416 (1961)
Packard, T.T., D. Blasco, J.J. MacIsaac and R.C. Dugdale: Variations of nitrate reductase activities in marine phytoplankton. Investigación pesq. 35, 309–319 (1971)
Painter, H.A.: A review of literature on inorganic nitrogen metabolism in micro-organisms. Wat. Res. 4, 393–450 (1970)
Payne, W.J.: Reduction of nitrogenous oxides by microorganisms. Bact. Rev. 37, 409–452 (1973)
Van't Riet, J., A.H. Stouthamer and R.L. Planta: Regulation of nitrate assimilation and nitrate respiration in Aerobacter aerogenes. J. Bact. 96, 1455–1464 (1968)
Vega, J.M., M.G. Guerrero, G. Leadbetter and M. Losada: Reduced nicotinamide adenine dinuleotide-nitrite reductase from Azotobacter chroococcum. Biochem. J. 133, 701–708 (1973)
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Communicated by J. H. S. Blaxter, Oban
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Brown, C.M., Macdonald-Brown, D.S. & Stanley, S.O. Inorganic nitrogen metabolism in marine bacteria: Nitrate uptake and reduction in a marine pseudomonad. Mar. Biol. 31, 7–13 (1975). https://doi.org/10.1007/BF00390642
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DOI: https://doi.org/10.1007/BF00390642