Azotobacter vinelandii

Azotobacter vinelandii is Gram-negative diazotroph that can fix nitrogen while grown aerobically.[2][3] It is a genetically tractable system that is used to study nitrogen fixation. These bacteria are easily cultured and grown.

Azotobacter vinelandii
Scientific classification
Kingdom:
Bacteria
Phylum:
Proteobacteria
Class:
Gammaproteobacteria
Order:
Pseudomonadales
Family:
Pseudomonadaceae
Genus:
Azotobacter
Species:
A. vinelandii
Binomial name
Azotobacter vinelandii

A. vinelandii is a free-living N2 fixer known to produce many phytohormones and vitamins in soils. It produces fluorescent pyoverdine pigments.[4]

The nitrogenase holoenzyme of A. vinelandii has been characterised by X-ray crystallography in both ADP tetrafluoroaluminate-bound[5] and MgATP-bound[6] states. The enzyme possesses molybdenum iron-sulfido cluster cofactors (FeMoco) as active sites, each bearing two pseudocubic iron-sulfido structures.

Variable ploidy

A. vinelandii can contain up to 80 chromosome copies per cell.[7] However this is only seen in fast growing culture, whereas cultures grown in synthetic minimal media are not polyploid.[8]

References
  1. William A. Noyes, ed. (1904). Review of American Chemical Research. 10. p. 75.
  2. Young, Mark. "Why it is possible to reduce Nitrogen fertilizers by using Azotobacter sp". Retrieved 14 June 2018.
  3. Requena N, Baca TM, Azcon R (1997). "Evolution of humic substances from unripe compost during incubation with lignolytic or cellulolytic microorganisms and effects on the lettuce growth promotion mediated by Azotobacter chroococcum". Biol Fertil Soils. 24: 59–65.
  4. 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. doi:10.1007/bf01141185.
  5. Schindelin H, Kisker C, Schlessman JL, Howard JB, Rees DC (1997). "Structure of ADP x AIF4(-)-stabilized nitrogenase complex and its implications for signal transduction". Nature. 387: 370–376. doi:10.1038/387370a0.
  6. Chiu H, Peters JW, Lanzilotta WN, Ryle MJ, Seefeldt LC, Howard JB, Rees DC (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. doi:10.1021/bi001645e.
  7. Nagpal P, Jafri S, Reddy MA, Das HK (1989). "Multiple chromosomes of Azotobacter vinelandii". J. Bacteriol. 171 (6): 3133–8. doi:10.1128/jb.171.6.3133-3138.1989. PMC 210026. PMID 2785985.
  8. Maldonado R, Jiménez J, Casadesús J (1994). "Changes of ploidy during the Azotobacter vinelandii growth cycle" (PDF). J. Bacteriol. 176 (13): 3911–9. doi:10.1128/jb.176.13.3911-3919.1994. PMC 205588. PMID 8021173.


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