Azotobacter vinelandii

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Scientific classification
Kingdom: Bacteria
Phylum: Proteobacteria
Class: Gammaproteobacteria
Order: Pseudomonadales
Family: Pseudomonadaceae
Genus: Azotobacter
Species: A. vinelandii
Binomial name
Azotobacter vinelandii

Azotobacter vinelandii is Gram-negative diazotroph that can fix nitrogen while grown aerobically. It is a genetically tractable system that is used to study nitrogen fixation. These bacteria are easily cultured and grown.

A. vinelandii is a free-living N2 fixer known to produce many phytohormones and vitamins in soils. It produces fluorescent pyoverdine pigments.[2]

The nitrogenase holoenzyme of A. vinelandii has been characterised by X-ray crystallography in both ADP tetrafluoroaluminate-bound[3] and MgATP-bound[4] states. The enzyme possesses molybdenum iron-sulfido cluster cofactors (FeMoco) as active sites, each bearing two pseudocubic iron-sulfido structures.

Variable ploidy[edit]

A. vinelandii can contain up to 80 chromosome copies per cell.[5] However this is only seen in fast growing culture, whereas cultures grown in synthetic minimal media are not polyploid.[6]


  1. ^ William A. Noyes, ed. (1904). Review of American Chemical Research. 10. p. 75. 
  2. ^ Menhart, N., Thariath, A., Viswanatha, T. (1991) Characterization of the pyoverdines of Azotobacter vinelandii ATCC 12837 with regard to heterogeneity. Biology of Metals 4(4):223-32
  3. ^ Schindelin, H., Kisker, C., Schlessman, J.L., Howard, J.B., Rees, D.C. (1997) Structure of ADP x AIF4(-)-stabilized nitrogenase complex and its implications for signal transduction. Nature 387: 370-376
  4. ^ Chiu, H., Peters, J.W., Lanzilotta, W.N., Ryle, M.J., Seefeldt, L.C., Howard, J.B., Rees, D.C. (2001) MgATP-Bound and nucleotide-free structures of a nitrogenase protein complex between the Leu 127 Delta-Fe-protein and the MoFe-protein. Biochemistry 40: 641-650
  5. ^ Nagpal P, Jafri S, Reddy MA, Das HK (1989). "Multiple chromosomes of Azotobacter vinelandii". J. Bacteriol. 171 (6): 3133–8. PMC 210026Freely accessible. PMID 2785985. 
  6. ^ Maldonado R, Jiménez J, Casadesús J (1994). "Changes of ploidy during the Azotobacter vinelandii growth cycle". J. Bacteriol. 176 (13): 3911–9. PMID 8021173. 

External links[edit]