1887

Abstract

grown with nitrate as nitrogen source had high nitrate reductase activity. During nitrogen starvation the rate of nitrate assimilation increased but the specific activity of nitrate reductase in extracts decreased sharply; a similar decrease occurred after transfer to an ammonium medium. Organisms grown with ammonium as nitrogen source did not assimilate nitrate but acquired the ability to do so after nitrogen starvation; nitrate reductase activity in these organisms was initially very low but increased during nitrogen starvation and then decreased. After 18 hr of nitrogen starvation ammonium-grown and nitrate-grown organisms assimilated nitrate rapidly at a rate some ten times greater than the activity of nitrate reductase in cell-free extracts would allow. The specific activity of glutamic dehydrogenase was about 40% higher in extracts from ammonium-grown organisms than in extracts from nitrate-grown organisms and its activity increased by 40-100 % during nitrogen starvation. The activity of malic dehydrogenase was unaffected by 18 hr of nitrogen starvation. The activity of isocitrate lyase decreased by about one-quarter when acetate was present but decreased much more markedly when the organisms were nitrogen-starved in the presence of glucose.

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/content/journal/micro/10.1099/00221287-38-1-21
1965-01-01
2021-10-20
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References

  1. Barratt R. W. 1963; Effect of environmental conditions on the NADP-specific glutamic acid dehydrogenase in Neurospora crassa. J. gen. Microbiol. 33:33
    [Google Scholar]
  2. Bongers L. H. J. 1956; Aspects of nitrogen assimilation by cultures of green algae.. Meded. LandbHoogesch., Wageningen 56:1
    [Google Scholar]
  3. Lowry O. H., Rosebrough N. J., Farr A. L., Randall R. J. 1951; Protein measurement with the Folin phenol reagent.. J. biol. Chem. 193:265
    [Google Scholar]
  4. Morris I., Syrett P. J. 1963; The development of nitrate reductase in Chlorella and its repression by ammonium.. Arch. Mikrobiol. 47:32
    [Google Scholar]
  5. Morton A. G., Dickerson F., England D. J. F. 1960; Changes in enzyme activity of fungi during nitrogen starvation.. J. exp. Bot. 11:116
    [Google Scholar]
  6. Sims A. P., Folkes B. F. 1964; A kinetic study of the assimilation of [15N]-ammonia and the synthesis of amino-acids in an exponentially growing culture of Candida utilis. Proc. roy. Soc. B:159–479
    [Google Scholar]
  7. Spiegelman S., Reiner J. M. 1947; The formation and stabilization of an adaptive enzyme in the absence of its substrate.. J. gen. Physiol. 31:175
    [Google Scholar]
  8. Syrett P. J. 1953; The assimilation of ammonia by nitrogen-starved cells of Chlorella vulgaris. I.. Ann. Bot., Lond. 17:1
    [Google Scholar]
  9. Syrett P. J. 1956; The assimilation of ammonia and nitrate by nitrogen-starved cells of Chlorella vulgaris. II. The assimilation of large quantities of nitrogen.. Physiol. Plant. 9:19
    [Google Scholar]
  10. Syrett P. J., Merrett M. J., Bocks S. M. 1963; Enzymes of the glyoxylate cycle in Chlorella vulgaris. J. exp. Bot. 14:249
    [Google Scholar]
  11. Syrett P. J., Morris I. 1963; The inhibition of nitrate assimilation by ammonium in Chlorella. Biochim. biophys. Acta 67:566
    [Google Scholar]
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