1887

Abstract

SUMMARY: The enzymes involved in the assimilation of ammonia by free-living cultures of spp. are glutamine synthetase (EC. 6.3.1.2), glutamate synthase (-glutamine: 2-oxoglutarate amino transferase) and glutamate dehydrogenase (EC 1.4.1.4). Under conditions of ammonia or nitrate limitation in a chemostat the assimilation of ammonia by cultures of and proceeded via glutamine synthetase and glutamate synthase. Under glucose limitation and with an excess of inorganic nitrogen, ammonia was assimilated via glutamate dehydrogenase, neither glutamine synthetase nor glutamate synthase activities being detected in extracts. The coenzyme specificity of glutamate synthase varied according to species, being linked to NADP for the fast-growing and but to NAD for the slow-growing and

Glutamine synthetase, glutamate synthase and glutamate dehydrogenase activities were assayed in sonicated bacteroid preparations and in the nodule supernatants of and nodules. All bacteroid preparations, except those from and , contained glutamate synthase but substantial activities were found only in and . The glutamine synthetase activities of bacteroids were low, although high activities were found in all the nodule supernatants. Glutamate dehydrogenase activity was present in all bacteroid samples examined. There was no evidence for the operation of the glutamine synthetase/glutamate synthase system in ammonia assimilation in root nodules, suggesting that ammonia produced by nitrogen fixation in the bacteroid is assimilated by enzymes of the plant system.

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1975-01-01
2024-04-25
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References

  1. Bergersen F. J. 1965; Ammonia - an early stable product of nitrogen fixation by soybean root nodules. Australian Journal of Biological Sciences 18:1–9
    [Google Scholar]
  2. Bergersen F. J., Turner G. L. 1967; Nitrogen fixation by the bacteroid fraction of breis of soybean root nodules. Biochimica et biophysica acta 141:507–515
    [Google Scholar]
  3. Broughton W. J., Dilworth M. J. 1971; Control of leghaemoglobin synthesis in snake beans. Biochemical Journal 125:1075–1080
    [Google Scholar]
  4. Brown C. M., Dilworth M. J. 1974; Ammonia assimilation during the growth of some microorganisms on nitrate. Proceedings of the Society for General Microbiology 12
    [Google Scholar]
  5. Brown C. M., MacDonald-Brown D. S., Meers J. L. 1974; Physiological aspects of microbial inorganic nitrogen metabolism. Advances in Microbial Physiology 11:1–52
    [Google Scholar]
  6. Brown C. M., MacDonald-Brown D. S., Stanley S. D. 1972; Inorganic nitrogen metabolism in marine bacteria: nitrogen assimilation in some marine pseudomonads. Journal of the Marine Biological Association of the United Kingdom 52:793–804
    [Google Scholar]
  7. Brown C. M., Macdonald-Brown D. S., Stanley S. O. 1973; The mechanism of nitrogen assimilation in pseudomonads. Antonie van Leeuwenhoek 39:89–98
    [Google Scholar]
  8. Brown C. M., Rose A. H. 1969; Effects of temperature on composition and cell volume of Candida utilis. Journal of Bacteriology 97:261–272
    [Google Scholar]
  9. Dainty R. H. 1972; Glutamate biosynthesis in Clostridium pasteurianum and its significance in nitrogen metabolism. Biochemical Journal 126:1055–1056
    [Google Scholar]
  10. Drozd J. W., Tubb R. S., Posgate J. R. 1972; A chemostat study of the effect of fixed nitrogen sources on nitrogen fixation, membranes and free amino acids in Azotobacter chroococcum. Journal of General Microbiology 73:221–232
    [Google Scholar]
  11. Dunn S. D., Klucas R. V. 1973; Studies on possible routes of ammonium assimilation in soybean root nodule bacteroids. Canadian Journal of Microbiology 19:1493–1499
    [Google Scholar]
  12. Fottrell P. F., Mooney P. 1969; The regulation of some enzymes involved in ammonia assimilation by Rhizobium japonicum. Journal of General Microbiology 59:211–214
    [Google Scholar]
  13. Grimes H., Fottrell P. F. 1966; Enzymes involved in glutamate metabolism in legume root nodules. Nature; London: 212295–296
    [Google Scholar]
  14. Grimes H., Turner S. 1971; Qualitative and quantitative studies of some enzymes in the nodule, root and shoot of Pisum sativum. Plant and Soil 35:269–273
    [Google Scholar]
  15. Kennedy I. R. 1966; Primary products of symbiotic nitrogen fixation. II. Pulse labelling of serradella nodules with 15N2. Biochimica et biophysica acta 130:295–308
    [Google Scholar]
  16. Kennedy I. R. 1973; Glutamine synthetase/glutamate synthetase for ammonia assimilation in symbiotic nitrogen fixation. Proceedings of the Australian Biochemical Society 633
    [Google Scholar]
  17. Kidby D. K. 1966; Activation of a plant invertase by inorganic phosphate. Plant Physiology 41:1139–1144
    [Google Scholar]
  18. Lowry O. H., Rosebrough N. J., Farr A. L., Randall R. J. 1951; Protein measurement with the Folin phenol reagent. Journal of Biological Chemistry 193:265–275
    [Google Scholar]
  19. Meers J. L., Pedersen L. K. 1972; Nitrogen assimilation in Bacillus licheniformis organisms growing in chemostat cultures. Journal of General Microbiology 70:277–286
    [Google Scholar]
  20. Meers J. L., Tempest D. W., Brown C. M. 1970; ‘Glutamine (amide): 2-oxoglutarate amino transferase oxidoreductase (NADP)’ an enzyme involved in the synthesis of glutamate by some bacteria. Journal of General Microbiology 64:187–194
    [Google Scholar]
  21. Miller R. E. 1973; Glutamate synthase from Escherichia coli: an iron-sulphide flavoprotein. In The Enzymes of Glutamine Metabolism pp. 293–318 Prusiner S., Stadtman E. R. Edited by New York: Academic Press;
    [Google Scholar]
  22. Nagatani H., Shimizu M., Valentine R. C. 1971; The mechanism of ammonia assimilation in nitrogen fixing bacteria. Archiv für Mikrobiologie 79:164–175
    [Google Scholar]
  23. Shapiro B. M., Stadtman E. R. 1970; The regulation of glutamine synthesis in micro-organisms. Annual Review of Microbiology 24:501–524
    [Google Scholar]
  24. Sloger C. 1973; Assimilation of ammonia by glutamine synthetase and glutamate synthetase in N2-fixing bacteroids from soybean nodules. Plant Physiology 51:534
    [Google Scholar]
  25. Tempest D. W., Meers J. L., Brown C. M. 1970; Synthesis of glutamate in Aerobacter aerogenes by a hitherto unknown route. Biochemical Journal 117:405–407
    [Google Scholar]
  26. Tempest D. W., Meers J. L., Brown C. M. 1973; Glutamate synthetase (GOGAT): a key enzyme in the assimilation of ammonia by prokaryotic organisms. In The Enzymes of Glutamine Metabolism pp. 167–182 Prusiner S., Stadtman E. R. Edited by New York: Academic Press;
    [Google Scholar]
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