1887

Abstract

SUMMARY: Studies of rates of consumption of dissolved O by suspensions of bacteroids (, strain 1809) from soybean root nodules showed the presence of two different terminal oxidase systems. A high-affinity system, sensitive to inhibition by -phenylimidazole and by carbon monoxide, was most active when the dissolved O was between 0·01 and 0·1 . At 1 -O or higher, this oxidase system had little activity and O was consumed largely by a low-affinity system insensitive to these inhibitors. At low concentrations of dissolved O, bacteroid respiration rates appeared to be diffusion-limited. When purified oxyleghaemo-globin was added to such systems, this restriction was relieved and respiration was maintained to much lower concentrations of free dissolved O here nitrogenase activity was greatest.

Analysis of reactions which were terminated at various stages during the depletion of O from oxyleghaemoglobin showed that at low free O concentration, the high-affinity pathway produced up to five times greater bacteroid ATP concentrations than the low-affinity oxidase pathway operating about 1 free O in the absence of leghaemoglobin. At intermediate free O concentrations, ocfnring during the later stages of deoxygenation of oxymyoglobin, intermediate concentrations of ATP were found in the bacteroids.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-91-2-345
1975-12-01
2021-07-28
Loading full text...

Full text loading...

/deliver/fulltext/micro/91/2/mic-91-2-345.html?itemId=/content/journal/micro/10.1099/00221287-91-2-345&mimeType=html&fmt=ahah

References

  1. Appleby C. A. 1969; Electron transport systems of Rhizobium japonicum. I. Haemoprotein P-450, other CO-reactive pigments, cytochromes and oxidases in bacteroids from N2-fixing root nodules. Biochimica et biophysica acta 172:71–87
    [Google Scholar]
  2. Appleby C. A., Bergersen F. J., Macnicol P. K., Turner G. L., Wittenberg B. A., Wittenberg J. B. 1975a; The role of leghaemoglobin in symbiotic N2 fixation. In Proceedings of an International Symposium on Nitrogen Fixation: Interdisciplinary Discussions. Newton W. E., Nyman C. J. Edited by Pullman, U.S.A.:: Washington University Press.;
    [Google Scholar]
  3. Appleby C. A., Turner G. L., Macnicol P. K. 1975b; Involvement of oxyleghaemoglobin and cytochrome P-450 in an efficient oxidative phosphorylation pathway which supports nitrogen fixation in Rhizobium. Biochimica et biophysica acta 387:461–474
    [Google Scholar]
  4. Bergersen F. J. 1962; Effects of partial pressure of oxygen upon respiration and nitrogen fixation by soybean root nodules. Journal of General Microbiology 29:113–125
    [Google Scholar]
  5. Bergersen F. J. 1971; Biochemistry of symbiotic nitrogen fixation in legumes. Annual Review of Plant Physiology 22:121–140
    [Google Scholar]
  6. Bergersen F. J., Goodchild D. J. 1973; Location and concentration of leghaemoglobin in soybean root nodules. Australian Journal of Biological Sciences 26:741–756
    [Google Scholar]
  7. Bergersen F. J., Turner G. L. 1973; Kinetic studies of nitrogenase from soya-bean root nodule bacteroids. Biochemical Journal 131:61–75
    [Google Scholar]
  8. Bergersen F. J., Turner G. L. 1975; Leghaemoglobin and the supply of O2 to nitrogen-fixing root nodule bacteroids: studies of an experimental system with no gas phase. Journal of General Microbiology 89:31–47
    [Google Scholar]
  9. Bergersen F. J., Turner G. L., Appleby C. A. 1973; Studies of the physiological role of leghaemoglobin in soybean nodules. Biochemica et biophysica acta 292:271–282
    [Google Scholar]
  10. Gourret J. P., Fernandez-Arias H. 1974; Étude ultrastructurale et cytochimique de la différentiation des bactéroides de Rhizobium trifoliiDangearddans les nodules de Trifolium repens L. Canadian Journal of Microbiology 20:1169–1181
    [Google Scholar]
  11. Hardy R. W. F., Holsten R. D., Jackson E. K., Burns R. C. 1968; The acetylene-ethylene assay for N-fixation; laboratory and field evaluation. Plant Physiology 43:1185–1207
    [Google Scholar]
  12. Postgate J. R. 1974; Prerequisites for biological nitrogen fixation in free-living heterotrophic bacteria. In Frontiers of Biology 33 The Biology of Nitrogen Fixation. Quispel A. Edited by Amsterdam: North-Holland Publishing.;
    [Google Scholar]
  13. Stanley P. E., Williams S. G. 1969; Use of the liquid scintillation spectrometer for determining adenosine triphosphate by the luciferase enzyme. Analytical Biochemistry 29:381–392
    [Google Scholar]
  14. Stokes A. N. 1975; Facilitated diffusion; the elasticity of oxygen supply. Journal of Theoretical Biology 52:285–297
    [Google Scholar]
  15. Tjepkema J. D., Yocum C. S. 1973; Respiration and oxygen transport in soybean nodules. Planta 115:59–72
    [Google Scholar]
  16. Truchet G. 1972; Mise en évidence de l’activité peroxidasique dans les différentes zones des nodules radiculaires de pois (Pisum sativum L.). Localization de la leghémoglobine. Compte rendu hebdomadaire des séances de l’Académie des sciences 274:1290–1293
    [Google Scholar]
  17. Wittenberg J. B. 1970; Myoglobin-facilitated oxygen diffusion; role of myoglobin in oxygen entry into muscle. Physiological Reviews 50:559–636
    [Google Scholar]
  18. Wittenberg J. B., Bergersen F. J., Appleby C. A., Turner G. L. 1974; Facilitated diffusion of O2: the role of oxyleghemoglobin in nitrogen fixation by bacteroids isolated from soybean root nodules. Journal of Biological Chemistry 249:4057–4066
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-91-2-345
Loading
/content/journal/micro/10.1099/00221287-91-2-345
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