International Code of Nomenclature of Prokaryotes

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. By 2020, there were three proposals for how to resolve the situation: • Exclude cyanobacteria from the bacteriological code. • Apply the bacteriological code to all cyanobacteria. • Treat valid publication under the botanical code as valid publication under the bacteriological code. In 2021, the ICSP held a formal vote on the three proposals and the third option was chosen. ==Type strain==

Since 2001, when a new bacterial or archaeal species is described, a type strain must be designated. 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 public culture collection in at least two different countries. Before 2001, a species could also be typified using a description, a preserved specimen, or an illustration. When a prokaryotic species cannot be cultivated in the laboratory (and therefore cannot be deposited in a culture collection), it may be given a provisional Candidatus name, but is not considered validly published. 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 the INSDC, or a single-gene sequence deposited to the INSDC. Pro-legitimate Candidatus names compete with each other for priority, but do not compete with "real" legitimate names. Before the pro-valid publication mechanism, the validation of Candidatus names fell to the Code of Nomenclature of Prokaryotes Described from Sequence Data (SeqCode) which is published by the International Society for Microbial Ecology, an organization separate from the ICSP, in 2022. == Other notable differences from the Botanical Code ==

Notable differences in rules: • Hyphenation is not allowed. Previously hyphenated names and new compounds are to be simply joined. • Diacritics are not allowed. There are fixed two-letter replacements for some letters with diacritics. 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. • There are no rank-specific rules for italicization in the ICNP. While many publishers choose to italicize genera and species only, the affiliated IJSEM and the ICNP text itself italicize all scientific names (with the exception of Candidatus-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. • The author citation term ex is to be used in parentheses, in the form "Taxon ". Subsequent revisions should be cited in the form "Taxon ". non should also be parenthesized, like in "Achromobacter (non Achromobacter )". ==Versions==

• 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. HathiTrust. • Reprinted 1949, Journal of General Microbiology 3, 444–462. • 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. • Parker, C.T., Tindall, B.J. & Garrity, G.M., eds. (2019). International Code of Nomenclature of Prokaryotes. Prokaryotic Code (2008 Revision). International Journal of Systematic and Evolutionary Microbiology 69(1A): S1–S111. doi: 10.1099/ijsem.0.000778 • == See also ==