Genus Azotobacter

Name: Azotobacter Beijerinck 1901 (Approved Lists 1980)

Category, proposed as: genus, gen. nov.

Etymology: A.zo.to.bac’ter. N.L. neut. n. azotum, nitrogen; from French masc. n. azote, nitrogen; from Gr. pref. a-, not (inseparable prefix); from Gr. fem. n. zôê, life; from N.Gr. fem. n. azôê, not sustaining life; N.L. masc. n. bacter, a rod; N.L. masc. n. Azotobacter, a nitrogen rod

Gender, pronunciation (Latin): masculine (stem: Azotobacter-), a-zo-to-BAK-ter

Type species: Azotobacter chroococcum Beijerinck 1901 (Approved Lists 1980)

Conduct genome-based taxonomy of genus at TYGS

16S rRNA gene: Analyse FASTA

Effective publication: Beijerinck MW. Über oligonitrophile Mikroben. Zentralblatt für Bakteriologie, Parasitenkunde, Infektionskrankheiten und Hygiene, Abteilung II 1901; 7:561-582.

IJSEM list: Skerman VBD, McGowan V, Sneath PHA. Approved lists of bacterial names. Int J Syst Bacteriol 1980; 30:225-420.

Nomenclatural status: validly published under the ICNP

Taxonomic status: correct name

Risk group: 1

• Emendations:
  • Rudra and Gupta 2024 Rudra B, Gupta RS. Phylogenomics studies and molecular markers reliably demarcate genus Pseudomonas sensu stricto and twelve other Pseudomonadaceae species clades representing novel and emended genera. Front Microbiol 2023; 14:1273665. 🇨🇦 Oren A, Göker M. List of changes in taxonomic opinion no. 41. Notification of changes in taxonomic opinion previously published outside the IJSEM. Int J Syst Evol Microbiol 2025; 75:6561.

• Notes:
  • 🥇 Nomenclatural type of the family Azotobacteraceae Pribram 1933 (Approved Lists 1980). Publication: Pribram E. Klassification der Schizomyceten. F. Deuticke, Leipzig, 1933.
  • 🧕 Bergey et al. (1923) assigned this genus to the tribe "Azotobactereae". Publication: Bergey DH, Harrison FC, Breed RS, Hammer BW, Huntoon FM. Bergey's Manual of Determinative Bacteriology, 1st ed. The Williams and Wilkins Co., Baltimore, 1923.
  • 🧕 Breed et al. (1948) assigned this genus to the family "Azotobacteriaceae". Publication: Burkholder WH. Genus I. Pseudomonas Migula. Bacterial plant pathogens. In: Breed RS, Murray EGD, Hitchens AP (eds), Bergey's Manual of Determinative Bacteriology, 6th ed., The Williams & Wilkins Co, Baltimore, 1948, p. 82-150.
  • 🧕 Brenner et al. (2005) assigned this genus to the family Pseudomonadaceae Winslow et al. 1917 (Approved Lists 1980). Publication: Garrity GM, Bell JA, Lilburn T. Class III. Gammaproteobacteria class. nov. In: Brenner DJ, Krieg NR, Staley JT, Garrity GM (eds), Bergey's Manual of Systematic Bacteriology, 2nd edn, vol. 2 (The Proteobacteria), part B (The Gammaproteobacteria), Springer, New York, 2005, p. 1. 🇺🇸
  • 🧕 Cavalier-Smith (1981) assigned this genus to the subkingdom "Eubacteria" Cavalier-Smith 1981. Publication: Cavalier-Smith T. Eukaryote kingdoms: seven or nine? Biosystems 1981; 14:461-481.
  • 🧕 Flores-Felix et al. (2025) assigned this genus to the family Pseudomonadaceae Winslow et al. 1917 (Approved Lists 1980). Publication: Flores-Felix JD, Garcia-Fraile P, Saati-Santamaria Z. Harmony in diversity: Reorganizing the families within the order Pseudomonadales. Mol Phylogenet Evol 2025; 0:108321. 🇪🇸
  • 🧕 Kluyver and Van Niel (1936) assigned this genus to the tribe Pseudomonadeae Kluyver and Van Niel 1936 (Approved Lists 1980). Publication: Kluyver AJ, Van Niel CB. Prospects for a natural system of classification of bacteria. Zentralblatt für Bakteriologie, Parasitenkunde, Infektionskrankheiten und Hygiene, Abteilung II 1936; 94:369-403.
  • 🧕 Winslow et al. (1920) assigned this genus to the tribe "Azotobactereae". Publication: Winslow CE, Broadhurst J, Buchanan RE, Krumwiede C, Rogers LA, Smith GH. The Families and Genera of the Bacteria: Final Report of the Committee of the Society of American Bacteriologists on Characterization and Classification of Bacterial Types. J Bacteriol 1920; 5:191-229.
  • 🙄 This taxon name is occasionally misprinted (or affected by an OCR error) in some sources as: "Asotobacter"; "Axotobacter"; "Azatobacter"; "Azofobacter"; "Azoiobacter"; "Azolobacter"; "Azotobacier"; "Azotobaclcr"; "Azotobactcr"; "Azotobaeter"; "Azotodacter"; "Azotollacter". — 🤨 This taxon name is occasionally used in plural form as: "Azotobacteria".
  • 🎰 The BRCs most frequently used for deposits in this group are: DSM: 11; ATCC: 10; JCM: 9; LMG: 8; NRRL: 8; NBRC: 5; NCAIM: 5; VKM: 4; CIP: 3; NCCB: 2.
  • 😷 The risk group for Canada has been imported on 2024-02-27. The full classification is: risk group = 1, note = "Animal classification RG: 1 - Security sensitive biological agent: No - Terrestrial animal pathogen under Canadian Food Inspection Agency authority: No - Containment level: Containment Level 1". — If in doubt, use the risk group given in the regulations for your country and, if these are not available, use the risk group given in the catalogue of the culture collection from which you have obtained or intend to obtain the strain.
  • 🧍 Pittman et al. (1991) suggested the abbreviation "AZBT" for this genus name but this does not appear to be of practical relevance any longer. Publication: Pittman KF, Walczak CA, Lock CM. Codes and abbreviations for approved of effectively published names of genera of bacteria published from January 1980 to December 1990. Int J Syst Bacteriol 1991; 41:571-579.
  • 🧍 A consideration of the phenotypic determinative characteristics of the genera Azomonas Winogradsky 1938 (Approved Lists 1980) and Azotobacter Beijerinck 1901 (Approved Lists 1980) supports the synonymy of these genera as indicated by the sequence data. An investigation of these two genera, with a wider selection of strains, including the type species of Azomonas (Azomonas agilis), and perhaps based on other genes, might support their synonymy. If they are established as a single genus, Azotobacter would take priority over Azomonas. At the molecular level, the similarity of Azotobacter species housekeeping gene and 16S rRNA gene sequences with those of Pseudomonas, especially Pseudomonas aeruginosa (the type species of the genus), point to an intimate relationship between these taxa. Publication: Young JM, Park DC. Probable synonymy of the nitrogen-fixing genus Azotobacter and the genus Pseudomonas. Int J Syst Evol Microbiol 2007; 57:2894-2901. 🇳🇿

Subdivision:

Number of child taxa with a validly published and correct name: 7
Number of child taxa with a validly published name, including synonyms: 9
Total number of child taxa: 17

• Child taxa:

  • Name	Nomenclatural status	Taxonomic status
    "Azotobacter acidum" Roy 1958	not validly published	synonym
    "Azotobacter agilis" Beijerinck 1901	not validly published, basonym of name in Approved Lists	synonym
    Azotobacter armeniacus Thompson and Skerman 1981	validly published under the ICNP	correct name
    Azotobacter beijerinckii corrig. Lipman 1904 (Approved Lists 1980)	validly published under the ICNP	correct name
    Azotobacter beyerincki Lipman 1904 (Approved Lists 1980)	inaccurate spelling	misspelling
    Azotobacter bryophylli Liu et al. 2019	validly published under the ICNP	correct name
    Azotobacter chroococcum Beijerinck 1901 (Approved Lists 1980)	validly published under the ICNP	correct name
    "Azotobacter indicum" Starkey and De 1939	not validly published, basonym of name in Approved Lists	synonym
    "Azotobacter insigne" Derx 1951	not validly published, basonym of name in Approved Lists	synonym
    "Azotobacter lacticogenes" Kauffmann and Toussaint 1951	not validly published	preferred name
    Azotobacter macrocytogenes Jensen 1955 (Approved Lists 1980)	validly published under the ICNP	synonym
    "Azotobacter miscellum" Varbanets et al. 1974	not validly published	preferred name
    Azotobacter nigricans Krassilnikov 1949 (Approved Lists 1980)	validly published under the ICNP	correct name
    Azotobacter paspali Döbereiner 1966 (Approved Lists 1980)	validly published under the ICNP	synonym
    Azotobacter salinestris Page and Shivprasad 1991	validly published under the ICNP	correct name
    "Azotobacter tropicalis" Leaungvutiviroj et al. 2010	not validly published	preferred name
    Azotobacter vinelandii Lipman 1903 (Approved Lists 1980)	validly published under the ICNP	correct name

Parent taxon: Azotobacteraceae Pribram 1933 (Approved Lists 1980)

Assigned by: Parker CD. Genus V. Thiobacillus Beijerinck 1904. In: Breed RS, Murray EGD, Smith NR (eds), Bergey's Manual of Determinative Bacteriology, 7th edition, The Williams & Wilkins Co, Baltimore, 1957, p. 83-88.

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Record number: 516974

• Previous versions:

  • Version	Date	JSON
    1	2026-03-31
    2	2026-06-16