Bradyrhizobium japonicum

Bradyrhizobium japonicum
Bradyrhizobium japonicum strain USDA 110 on an agar plate.
Scientific classification
Kingdom: Bacteria
Phylum: Proteobacteria
Class: Alphaproteobacteria
Order: Rhizobiales
Family: Bradyrhizobiaceae
Genus: Bradyrhizobium
Species: B. japonicum
Binomial name
Bradyrhizobium japonicum
(Kirchner 1896) Jordan, 1982
Synonyms

Rhizobium japonicum Buchanan 1926
Rhizobacterium japonicum Kirchner 1896[1]

Bradyrhizobium japonicum is a species of legume-root nodulating, microsymbiotic nitrogen-fixing bacterium species. B. japonicum is identified as a DNA homology group (group II)[2].

B. japonicum is able to degrade catechin with formation of phloroglucinol carboxylic acid, further decarboxylated to phloroglucinol, which is dehydroxylated to resorcinol and hydroxyquinol.

B. japonicum possess the nosRZDFYLX gene, which aides in denitrification and has two catalytic subunits - Cu-a and Cu-z (with several histidine residues). It manages an expression cascade that can sense oxygen gradients, termed 'FixJ-FixK2-FixK1.' FixJ positively regulates FixK2, which activates nitrogen respiration genes as well as FixK1. FixK1 mutants are unable to respire from nitrogen due to a defective catatylic copper subunit (Cu-z) in nosRZDFYLX.[3].

References

  1. ^ Transfer of Rhizobium japonicum Buchanan 1980 to Bradyrhizobium gen. nov., a genus of slow-growing, root nodule bacteria from leguminous plants. Int. J. Syst. Bacteriol., 1982, 32, 136-139.
  2. ^ A. B. Hollis, W. E. Kloos & G. E. Elkan (1981). "DNA:DNA hybridization studies of Rhizobium japonicum and related Rhizobiaceae". Journal of General Microbiology 123: 215–222. 
  3. ^ D. Nellen-Anthamatten, P. Rossi, et al. (1998). "Bradyrhizobium japonicum, FixK2, a Crucial Distributor in the FixLJ-Dependent Regulatory Cascade for Control of Genes Inducible by Low Oxygen Levels". [Journal of Bacteriology] 180(19): 5251-5255. 

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