1887

Abstract

SUMMARY: , like , has a methionine-regulated β-aspartokinase and homoserine dehydrogenase in addition to threonine-sensitive and lysine-sensitive aspartokinase isoenzymes and a threonine-sensitive homoserine dehydrogenase. These methionine-regulated enzymes are not subject to feedback inhibition by methionine (or by methionine and S-adenosylmethionine), but the homoserine dehydrogenase is inhibited by the methionine precursor cysteine and to a lesser extent by homocysteine. Studies of enzyme concentrations in methionine analogue-resistant strains show that mutations which lead to de-repression of the later methionine-forming enzymes also result in de-repressed synthesis of the methionine-regulated β-aspartokinase and homoserine dehydrogenase, although the methionine-forming enzymes as a whole are not subject to co-ordinate control.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-54-3-337
1968-12-01
2024-12-12
Loading full text...

Full text loading...

/deliver/fulltext/micro/54/3/mic-54-3-343.html?itemId=/content/journal/micro/10.1099/00221287-54-3-337&mimeType=html&fmt=ahah

References

  1. BURBANCK W. D. 1942; Physiology of the ciliate Colpidium colpoda. I. The effect of various bacteria as food on the division rate of Colpidium colpoda.. Physiol. Zoöl. 15:342
    [Google Scholar]
  2. COLEMAN G. S. 1964; The metabolism of Escherichia coli and other bacteria by Entodinium caudatum.. J. gen, Microbiol. 37:209
    [Google Scholar]
  3. CONTOIS D. E. 1959; Kinetics of bacterial growth: relationship between population density and specific growth rate of continuous cultures.. J. gen. Microbiol. 21:40
    [Google Scholar]
  4. Cox F. E. G. 1967; A quantitative method for measuring the uptake of carbon particles by Tetrahymena pyriformis.. Trans. Am. microsc. Soc. 86:261
    [Google Scholar]
  5. CURDS C. R. 1963; The flocculation of suspended matter by Paramecium caudatum.. J. gen. Microbiol. 33:357
    [Google Scholar]
  6. CURDS C. R. 1967; Continuous culture. A method for the determination of food consumption by ciliated protozoa. In Proceedings of the Symposium on Methods of Study of Soil Ecology.. Ed. by J. Philipson. Paris; UNESCO. (In the Press.):
    [Google Scholar]
  7. CURDS C. R., VANDYKE J. M. 1966; The feeding habits and growth rates of some fresh-water ciliates found in activated-sludge plants.. J. appl. Ecol. 3:127
    [Google Scholar]
  8. CURDS C. R., COCKBURN A., VANDYKE J. M. 1968; An experimental study of the role of the ciliated protozoa in the activated-sludge process.. Wat. Pollut. Control 67:312
    [Google Scholar]
  9. CUTLER D. W., CRUMP L. M. 1924; The rate of reproduction in artificial culture of Colpidium colpoda.. Part III. Biochem. J. 18:905
    [Google Scholar]
  10. ENGELMANN M. D. 1961; The ro1e of soil arthropods in the energetics of an old field community.. Ecol. Monogr. 31:221
    [Google Scholar]
  11. HADJIPETROU L. P., GERRITS J. P., TEULINGS F. A. G., STOUTHAMER A. H. 1964; Relation between energy production and growth of Aerobacter aerogenes.. J. gen. Microbiol. 36:139
    [Google Scholar]
  12. HEAL O. W. 1967 a; Quantitative studies on soil amoebae.. In Progress in Soil Biology. Ed. by Graff O., Satchell J. E. p. 120 Amsterdam: North Holland Publ. Co.;
    [Google Scholar]
  13. HEAL O. W. 1967 b; Methods of study of soil protozoa. In Proceedings of the Symposium on Methods of Study of Soil Ecology.. Ed. by Philipson J. Paris: UNESCO. (In the Press.);
    [Google Scholar]
  14. HERBERT D., ELSWORTH R., TELLING R. C. 1956; The continuous culture of bacteria; a theoretical and experimental study.. J. gen. Microbiol. 14:601
    [Google Scholar]
  15. MACFADYEN A. 1963; Heterotrophic productivity in the detritus food chain in soil.. Proc. 16 int. Congr. Zool. 4:318
    [Google Scholar]
  16. MCMAHON J. W., RIGLER F. H. (1965); Feeding rate of Daphnia magna Straus in different foods labelled with radioactive phosphorus.. Limnol. Oceanogr. 10:105
    [Google Scholar]
  17. MONOD J. 1942; Recherches sur la Croissance des Cultures Bactériennes.. Paris: Hermann and Cie.;
    [Google Scholar]
  18. PILLAI S. C. 1942; Further studies on the role of the protozoa in the activated-sludge process.. Curr. Sci. 11:437
    [Google Scholar]
  19. PILLAI S. C., SUBRAHMANYAN V. 1944; The role of protozoa in the aerobic purification of sewage.. Nature, Lond. 154:179
    [Google Scholar]
  20. PROPER G., GARVER J. C. 1966; Mass culture of the protozoa Colpoda steinii.. Biotechnol. Bioengng 8:287
    [Google Scholar]
  21. RICHMAN S. 1958; The transformation of energy by Daphnia pulex.. Ecol. Monogr. 28:273
    [Google Scholar]
  22. SEAMAN G. R. 1955; Metabolism of free-living ciliates. In Biochemistry and Physiology of Protozoa.. Ed. by Hutner S. H., Lwoff A. Vol. 2,: p. 91
    [Google Scholar]
  23. SEAMAN G. R. 1961; Some aspects of phagotrophy in Tetrahymena.. J. Protozool. 8:212
    [Google Scholar]
/content/journal/micro/10.1099/00221287-54-3-337
Loading
/content/journal/micro/10.1099/00221287-54-3-337
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error