TheInternational Code of Nomenclature of Prokaryotes (ICNP) orProkaryotic Code, formerly theInternational Code of Nomenclature of Bacteria (ICNB) orBacteriological Code (BC), governs thescientific names forBacteria andArchaea.[1][2] It denotes the rules for namingtaxa of bacteria, according to their relative rank. As such it is one of thenomenclature codes ofbiology.
Originally theInternational Code of Botanical Nomenclature dealt with bacteria, and this kept references to bacteria until these were eliminated at the 1975International Botanical Congress. An early Code for the nomenclature of bacteria was approved at the 4th International Congress for Microbiology in 1947, but was later discarded.
The baseline for bacterial names is the Approved Lists[4] with a starting point of 1980. New bacterial names are reviewed by the ICSP as being in conformity with the Rules of Nomenclature and published in theIJSEM.
Since 1975, most bacteria were covered under the bacteriological code. However,cyanobacteria were still covered by the botanical code. Starting in 1999, cyanobacteria were covered by both the botanical and bacteriological codes. This situation has caused nomenclatural problems for the cyanobacteria.[5][6] By 2020, there were three proposals for how to resolve the situation:
Exclude cyanobacteria from the bacteriological code.[7]
Apply the bacteriological code to all cyanobacteria.[8]
Treat valid publication under the botanical code as valid publication under the bacteriological code.[9]
In 2021, the ICSP held a formal vote on the three proposals and the third option was chosen.[10]
Since 2001, when a new bacterial or archaeal species is described, a type strain must be designated.[11] The type strain is a living culture to which the scientific name of that organism is formally attached. For a new species name to be validly published, the type strain must be deposited in a publicculture collection in at least two different countries.[12] Before 2001, a species could also be typified using a description, a preserved specimen, or an illustration.[11] There is a single type strain for each prokaryotic species, but different culture collections may designate a unique name for the same strain. For example, the type strain ofE. coli (originally strain U5/41) is called ATCC 11775 by theAmerican Type Culture Collection, DSM 30083 by theGerman Collection of Microorganisms and Cell Cultures, JCM 1649 by theJapan Collection of Microorganisms, and LMG 2092 by theBelgian Coordinated Collections of Microorganisms.[13][14]
When a prokaryotic species cannot be cultivated in the laboratory (and therefore cannot be deposited in a culture collection), it may be given a provisionalCandidatus name, but is not considered validly published.[15] Since 2024, these names can be "pro-validly published" and become "pro-legitimate" and "pro-correct". This requires the name to meet most existing requirements for valid publication (and analogously for legitimacy and correctness),except the culture deposition in Rule 30 can be replaced by a living culture not meeting the requirements of Rule 30, a preserved specimen, a sequenced genome deposited on theINSDC, or a single-gene sequence deposited to the INSDC. Pro-legitimateCandidatus names compete with each other for priority, but do not compete with "real" legitimate names.[16]
Hyphenation is not allowed. Previously hyphenated names and new compounds are to be simply joined.[18]: Rule 12a
Diacritics are not allowed. There are fixed two-letter replacements for some letters with diacritics.[18]: Rule 64 There is no clarifying carve-out for diaeresis (ë) like in Rule 60.7 of theShenzhen Code.[19]
Notable differences in recommended practice:
Scientific names are recommended to be differentiated "by a different type face, e.g., italic, or by some other device". Italicization is not mandatory.[18]: 4.A.(3)
There are no rank-specific rules for italicization in the ICNP. While many publishers choose to italicize genera and species only, the affiliatedIJSEM and the ICNP text itself italicize all scientific names (with the exception ofCandidatus-specific formatting).
Latin words or abbreviations that follow an italicized scientific name should not be italicized. They may be laid out in roman (regular) font, or in bold if differentiation is desired.[18]: Rule 33a:Note 2
The author citation termex is to be used in parentheses, in the form "Taxon(ex Earlier) Later". Subsequent revisions should be cited in the form "Taxon(Later ex Earlier) Subsequent".non should also be parenthesized, like in "AchromobacterYabuuchi and Yano 1981 (nonAchromobacterBergey et al. 1923)".[18]: 4.B.(3)
Buchanan, R. E., and Ralph St. John-Brooks. (1947, June) (Editors).Proposed Bacteriological Code of Nomenclature. Developed from proposals approved by International Committee on Bacteriological Nomenclature at the Meeting of the Third International Congress for Microbiology. Publication authorized in Plenary Session, pp. 61. Iowa State College Press, Ames, Iowa. U.S.A.Hathi Trust.
International Committee on Bacteriological Nomenclature. (1958, June).International code of nomenclature of bacteria and viruses. Ames, Iowa State College Press.BHL.
Lapage, S.P., Sneath, P.H.A., Lessel, E.F., Skerman, V.B.D., Seeliger, H.P.R. & Clark, W.A. (1975).International Code of Nomenclature of Bacteria. 1975 Revision. American Society of Microbiology, Washington, D.C.
Lapage, S.P., Sneath, P.H.A., Lessel, E.F., Skerman, V.B.D., Seeliger, H.P.R. & Clark, W.A. (1992).International Code of Nomenclature of Bacteria. Bacteriological Code. 1990 Revision. American Society for Microbiology, Washington, D.C.link.
^abP. H. A. Sneath, 2003. A short history of the Bacteriological CodeURLArchived 2012-05-24 at theWayback Machine
^Lapage, S. P.; Sneath, P. H. A.; Lessel, E. F.; Skerman, V. B. D.; Seeliger, H. P. R.; Clark, W. A. (March 5, 1992).Rules of Nomenclature with Recommendations. ASM Press – via ncbi.nlm.nih.gov.
^Oren A, Ventura S (2017). "The current status of cyanobacterial nomenclature under the "prokaryotic" and the "botanical" code".Antonie van Leeuwenhoek.110 (10):1257–1269.doi:10.1007/s10482-017-0848-0.PMID28243951.S2CID23489558.
^Oren A, Garrity GM (2014). "Proposal to change General Consideration 5 and Principle 2 of the International Code of Nomenclature of Prokaryotes".Int J Syst Evol Microbiol.64 (1):309–10.doi:10.1099/ijs.0.059568-0.PMID24408952.
