Ammonia Assimilation in Colonial Derivatives Differing in Nitrogen-fixing Efficiency Free

Abstract

SUMMARY: Ammonia assimilatory activities were investigated in cultures of small, efficient nitrogen-fixing derivatives (110-I, 76-) and large, inefficient nitrogen-fixing derivatives (110- , 76-) of strains 3I1b110 and 6176. Specific activities of the key ammonia assimilatory enzymes, glutamine synthetase (EC 6.3.1.2), glutamate synthase (EC 2.6.1.53) and glutamate dehydrogenase (EC 1.4.1.2), were determined in aerobic, microaerophilic and bacteroid cell-free extracts. In aerobic culture, 110- and 76- assimilated more ammonia than 110-I and 76- because of apparent twofold or greater assimilatory enzyme activities. Specific ammonia assimilatory enzyme activities were 10- to 100-fold lower for all derivatives in nitrogen-fixing microaerophilic and bacteroid cultures. In addition to these already low ammonia assimilatory activities, the assimilatory activities of 110-I and 76- were twofold lower than those of 110- and 76-. The small colony types also excreted ammonia under nitrogen-fixing conditions.

These findings support the idea that rhizobia can simultaneously derepress nitrogenase biosynthesis whilst repressing ammonia assimilatory enzyme biosynthesis. This investigation has also linked the efficiency of ammonia assimilation with the efficiency of nitrogenase activity as an inverse function, i.e. those derivatives that fix greater amounts of nitrogen also assimilate less fixed nitrogen.

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1978-02-01
2024-03-29
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References

  1. Bergersen I. 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]
  2. Bishop P. E., Guevara J. G., Engelke J. A., Evans H. J. 1976; Relation between glutamine synthetase and nitrogenase activities in the symbiotic association between Rhizobium japonicum and Glycine max. Plant Physiology 57:542–546
    [Google Scholar]
  3. Brill W. J. 1975; Regulation and genetics of bacterial nitrogen fixation. Annual Review of Microbiology 29:109–129
    [Google Scholar]
  4. Brown C. M., Dilworth M. J. 1975; Ammonia assimilation by Rhizobium cultures and bacteroids. Journal of General Microbiology 86:39–48
    [Google Scholar]
  5. Chaney A. L., Marbach E. P. 1962; Modified reagents for determination of urea and ammonia. Clinical Chemistry 8:130–132
    [Google Scholar]
  6. Keister D. L. 1975; Acetylene reduction by pure cultures of rhizobia. Journal of Bacteriology 123:1265–1268
    [Google Scholar]
  7. Keister D. L., Evans W. R. 1976; Oxygen requirement for acetylene reduction by pure cultures of rhizobia. Journal of Bacteriology 129:149–153
    [Google Scholar]
  8. Kurz W. G. W., La Rue T. A. 1975; Nitrogenase activity in absence of plant host. Nature; London: 256407–408
    [Google Scholar]
  9. Kurz W. G. W., Rokosh D. A., La Rue T. A. 1975; Enzymes of ammonia assimilation in Rhizobium leguminosarum bacteroids. Canadian Journal of Microbiology 21:1009–1012
    [Google Scholar]
  10. Kuykendall L. D., Elkan G. H. 1976; Rhizobium japonicum derivatives differing in nitrogen fixing efficiency and carbohydrate utilization. Applied and Environmental Microbiology 32:511–519
    [Google Scholar]
  11. Kuykendall L. D., Elkan G. H. 1977; Some features of mannitol metabolism in Rhizobium japonicum. Journal of General Microbiology 98:291–295
    [Google Scholar]
  12. Layne E. 1957; Spectrophotometric and turbidometric methods for measuring protein. Methods in Enzymology 3:447–454
    [Google Scholar]
  13. Lillich T. T., Elkan G. H. 1968; Evidence countering the role of polygalacturonase in invasion of root hairs of leguminous plants by Rhizobium spp. Canadian Journal of Microbiology 14:617–625
    [Google Scholar]
  14. Mccomb J. A., Elliot J., Dilworth M. J. 1975; Acetylene reduction by Rhizobium in pure culture. Nature; London: 256409–410
    [Google Scholar]
  15. O’Gara R., Shanmugam K. T. 1976; Regulation of nitrogen fixation by Rhizobia export of fixed N2 as NH4+. Biochimica et biophysica acta 437:313–321
    [Google Scholar]
  16. Pagan J. D., Child J. J., Scrowcroft W. R., Gibson A. H. 1975; Nitrogen fixation by Rhizobium cultured on a defined medium. Nature; London: 256406–407
    [Google Scholar]
  17. Prusiner S., Miller R. E., Valentine R. C. 1972; Adenosine 3′:5′-cyclic monophosphate control of the enzymes of glutamine metabolism in Escherichia coli. Proceedings of the National Academy of Sciences of the United States of America 692922–2926
    [Google Scholar]
  18. Robertson J. G., Warburton M. P., Farnden W. J. F. 1975; Induction of glutamate synthetase during nodule development in lupin. FEBS Letters 55:33–37
    [Google Scholar]
  19. Shapiro B. M., Stadtman E. R. 1970; Glutamine synthetase (E. coli). Methods in Enzymology 17A:910–922
    [Google Scholar]
  20. Tjepkema J., Evans H. J. 1975; Nitrogen fixation by free-living Rhizobium in a defined liquid medium. Biochemical and Biophysical Research Communications 65:625–628
    [Google Scholar]
  21. Upchurch R. G., Elkan G. H. 1977; Comparison of colony morphology, salt tolerance and effectiveness in Rhizobium japonicum. Canadian Journal of Microbiology 23:1118–1122
    [Google Scholar]
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