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Most of the mistakes commonly made in naming newly discovered species (and genera) of prokaryotes (i.e.Bacteria and Archea/Eubacteria and Archaeobacteria) of transferring species from one to another genus can be avoided by following this advice:

(i) Gender of specific epithet

A common mistake is that, while forming new combinations (comb. nov.) by transferring a species to another genus, authors forget to change the gender of the specific epithet if that of the accepting genus differs from that of the former genus. The epithet has to follow the genus in gender!

Adjectival endings (suffixes) in Latin are in Table 1.

Hypothetical examples: If the species "Blocus limosus" would be transferred to the genus "Leucobacterium", it would become "L. limosum" (comb. nov.). If "Ercobacter mobilis" would be changed to "Aurigenium", it would have to become "A. mobile".

Note that names ending on -bacter are treated as masculine!
 

TABLE 1. Examples of Latin adjectives.

*Meaning: white, easy, rapid.

(ii) Genus names formed from personal names

These may be formed directly, or, alternatively, as a Latin diminutive, and are always feminine. Such Latin names depend on the ending of the respective personal name. Proceed according to Table 2.

Note that for names ending on -e and on -o different alternatives have been -and thus must be - used!

Some personal names in Europe were already latinized in the 18th century and earlier. If they end on -us, replace -us by -a or by -ella (diminutive form). Example: personal name Bucerius, organism's name "Buceria" or "Buceriella".

Examples for diminutive names are, e.g. Salmonella, Klebsiella, Shigella, "Catonella", "Mbutuella", "Deleyella".
 

TABLE 2. Ways to form generic names from personal names.
(Modified after TRÜPER (H.G.): How to name a prokaryote? Etymological considerations, proposals and practical advice in prokaryote nomenclature. FEMS Microbiol. Rev., 1999, 23, 231-249.)

(iii) Specific epithets formed from personal names

In principle there are two possibilities to proceed in either choosing the adjectival form (a) or the substantival form (b):

(a) Latinize the personal name according to column 2 of the preceding table and add the ending -nus (m.), -na (f.), -num (n.) according to the gender of the genus name. Thus you have formed an adjective that has the meaning of "pertaining, belonging to the person...".

(b) Latinize the name according to the sex of the person to be honored and form the genitive. To do this correctly, use the advice given in Table 3.

The problem with names ending on -a is that they may be latinized in four different ways (for example: the name MacKenna):

(i) Treat MacKenna as if it were a classical Latin name like Seneca. Then it follows the a-declination, and the genitive for Ms. or Mr. MacKenna would give the same specific epithet, namely mackennae, meaning "of MacKenna".

(ii) The other three possibilities allow to recognize the sex of the person the new organism is to be named after. Mr. MacKenna is latinized to Mackennaus, which results in the specific epithet mackennaei (only m.)

(iii) The name is latinized to Mackennaeus (m.) (like Linnaeus) or Mackennaea (f.) with the consequence that the specific epithet is mackennaei (m.) or mackennaeae (f.), respectively.

(iv) The name is latinized to Mackennaius (m.) or Mackennaia (f.) so that the specific epithet would be mackennaii (m.) or mackennaiae (f.), respectively.

The reader will understand that the latter two possibilities, although permissible, look and sound rather awkward and are due to produce a lot of misspellings. Therefore I strongly recommend to use the first two versions only.

Examples (partly hypothetical) for epithets derived from personal names are: smithii, maxwelliae, ottonis, ottonii, catoniae, novyi, daleyae, nealsonii, verdii, milleri, carpenterae, micdadei, postgatei, stanieri, dorotheae.
 

TABLE 3. Formation of specific epithets from personal names as genitive nouns
(Modified after TRÜPER (H.G.): How to name a prokaryote? Etymological considerations, proposals and practical advice in prokaryote nomenclature. FEMS Microbiol. Rev., 1999, 23, 231-249.)

(iv) Specific epithets derived from names of localities

These are used to indicate the place of origin or occurrence of organisms. They are constructed by adding to the locality's name the ending -ensis (m. or f.) or ense (n.) in agreement with the gender of the genus name. Only if the name of the locality ends on -a or -e, these vowels are dropped before the addition of -ensis/-ense. Examples: Thiospirillum jenense (from Jena).

Do not form epithets by use of the latinized locality's name in the genitive! (e.g. londoni instead of the correct londonensis).

Exceptions are those cases where there exist regular Latin adjectives that have been in used for countries, continents, rivers, cities, etc. at least since the middle ages, such as: europaeus, africanus, asiaticus, americanus, italicus, romanus (Rome), germanicus, britannicus, gallicus, polonicus, hungaricus, graecus, hispanicus, rhenanus (Rhine), frisius, saxonicus, bavaricus, bohemicus, mediterraneus (Mediterranean Sea), etc...

(v) Names combined from words of Greek and Latin origin

When names are combined from two or more words of Greek or/and Latin origin, there is an easy rule to follow:

a) If the first compound is Latin, the connecting vowel is an -i-, no matter whether a Greek or Latin compound follows.
Examples: rectivirgula, lactilyticus, avipneumoniae, omnivorans, Aquifex.

b) If the first compound is Greek, the connecting vowel is an -o-, no matter whether a Greek or Latin compound follows.
Examples: Halobacterium, chromofuscus, Pseudomonas, Leuconostoc.

c) If the second compound starts with a vowel, no extra connecting vowel is required.
Examples: acetoxidans, salexigens.

General advice: Consult the International Code of Nomenclature of Bacteria (1990 Revision), published in 1992 by the American Society for Microbiology, 1325 Massachusetts Ave. N.W., Washington, D.C., USA.
This consists of the Code itself plus 10 Appendices, of which especially Appendix 9 relates to the matters listed above.

If you really get a problem with a name, send me a fax (H.G. Trüper: +49-228-737576). I promise to help.