Genders of generic names

The author is very grateful to Dr. B.J. Tindall (DSMZ) and to Dr. N. Weiss (DSMZ) for their helpful comments.

. According to Rule 10a, the name of a genus is a substantive, or an adjective used as a substantive, in the singular number and written with an initial capital letter. The name may be taken from any source and may even be composed in an arbitrary manner. It is treated as a Latin substantive.
. Rule 65 of the Bacteriological Code (1990 Revision) states (i) that a Latin or Greek word adopted as a generic name retains the classical gender of its language of origin; (ii) that generic names which are modern compounds from two or more Latin or Greek words take the gender of the last component of the coumpound word; and (iii) that arbitrarily formed generic names or vernacular names used as generic names take the gender assigned to them by their authors.
. An adjective used as a substantive may be in the masculine, in the feminine or in the neuter gender. For example, Rhodoferax is in the masculine gender, Propioniferax is in the feminine gender and Haloferax is in the neuter gender.

References:
. LAPAGE (S.P.), SNEATH (P.H.A.), LESSEL (E.F.), SKERMAN (V.B.D.), SEELIGER (H.P.R.) and CLARK (W.A.): International Code of Nomenclature of Bacteria (1990 Revision). American Society for Microbiology, Washington, D.C., 1992.
. MacADOO (T.O.): Nomenclatural literacy. In: M. GOODFELLOW and A.G. O'DONNELL (eds.): Handbook of New Bacterial Systematics, Academic Press, London, 1993, pp. 339-358.
. TRÜPER (H.G.): Help! Latin! How to avoid the most common mistakes while giving Latin names to newly discovered prokaryotes. Microbiología (Sociedad Española de Microbiología), 1996, 12, 473-475. Also available on the Internet.
. TRÜPER (H.G.): How to name a prokaryote? Etymological considerations, proposals and practical advice in prokaryote nomenclature. FEMS Microbiol. Rev., 1999, 23, 231-249.
. TRÜPER (H.G.): Etymology in nomenclature of procaryotes. In: D.R. BOONE, R.W. CASTENHOLZ and G.M. GARRITY (eds.), Bergey's Manual of Systematic Bacteriology, second edition, vol. 1 (The Archaea and the deeply branching and phototrophic Bacteria), Springer-Verlag, New York, 2001, pp. 89-99.

Latin words or Neo-Latin words (mainly of Latin or Greek origin) adopted as generic names

. Amorphus: N.L. masc. n. amorphus from Gr. adj. amorphos, without form, shapeless.
. Bacillus: L. masc. n. bacillus -i, a small staff.
. Ensifer: N.L. masc. substantive from L. masc. adj. ensifer, sword-bearing.
. Inquilinus: L. masc. n. inquilinus -i, an inhabitant of a place which is not his own, a sojourner, tenant, lodger.
. Labrys: N.L. masc. n. from Gr. masc. n. labrus, two-edged axe, double-headed axe.
. Meniscus: N.L. masc. n. from Gr. masc. n. mêniskos, lunar crescent.
. Orbus: L. masc. n. orbus, an orphan.
. Pectinatus: N.L. masc. substantive from L. masc. adj. pectinatus, combed.
. Proteus: L. masc. n. Proteus -i, a prophet and god of the sea.
. Sodalis: L. masc. n. sodalis -is, a companion, comrade, a member of an association.
. Symbiotes: N.L. masc. n. from Gr. masc. n. sumbiôtês, one who lives with, companion, partner.
. Syntrophus: N.L. masc. n. from Gr. masc. n. syntrophos, foster brother [one reared in the same house].
. Thermus: N.L. masc. substantive from Gr. masc. adj. thermos, hot.
. Vibrio: N.L. masc. n. vibrio, that which moves rapidly, that which vibrates from L. v. vibro to move rapidly to and fro, to vibrate.

a) Genus names formed from personal names (see the file Genus names formed from personal names) are always feminine. Such names may be formed by addition of an ending or a diminutive ending.
. Endings: -a, -ea, -ia, -nia. The ending -ina has also been used by Bermudes et al. 1988 (see Clevelandina, Hollandina, Pillotina).
. Diminutive endings: -ella, -iella, -lla, -nella.
. These endings or diminutive endings are also used to form generic names from names of divinities: Amphritea (Gr. fem. n. Amphrite, a nymph of the ocean in Greek mythology), Demetria (N.L. fem. n. from Gr. n. Dêmêter, Greek female god of agriculture), Eudora (N.L. fem. n., named after Eudora, a sea goddess in Greek mythology), Haliea (N.L. fem. n., named after Halie, a sea nymph in Greek mythology), Hellea (L. fem. n. Helle, a sea goddess in Greek mythology), Melitea (N.L. fem. n. Melitea, named after Melite, a nymph of the sea in Greek mythology), Nereida (L. fem. n. Nereida, a Nereid, a sea nymph), Pandoraea (N.L. fem. n. from Gr. or L. fem. n. Pandora, a beautiful female, made by Hephaestus, who received presents from all the gods, in order to win the heart of Epimetheus), Persephonella (N.L. fem. n. from Gr. fem. n. Persephonê, a Greek mythological goddess), Telluria (N.L. fem. n. from L. n. Tellus -uris, a Roman goddess of the earth), ...
. For more information, see (i) H.G. Trüper: Help! Latin! How to avoid the most common mistakes while giving Latin names to newly discovered prokaryotes; (ii) Genus names formed from personal names.

b) Other names:
. Aegyptianella: N.L. fem. dim. n. (from L. fem. n. Aegyptus, Egypt), named after Egypt.
. Alysiella: N.L. fem. dim. n. (from Gr. neut. n. halusion, a small chain), a very small schain.
. Ampullariella: N.L. dim. n. (from L. masc. n. ampullarius, a bottle-maker), intended to mean a small bottle.
. Arachnia: N.L. fem. n. from Gr. fem. n. arachnê, a spider.
. Balneatrix: L. fem. n. balneatrix -icis, bather, she who has the care of a bath.
. Balneola: M.L. fem. n. balneola, the ancient name of Banyuls.
. Beutenbergia: N.L. fem. n. Beutenbergia, referring to Beutenberg.
. Brooklawnia: N.L. fem. n. Brooklawnia, referring to Brooklawn.
. Budvicia, N.L. fem. n. Budvicia, referring to Budvicium, the Latin name of the city Ceské Budejovice.
. Centipeda: L. fem. n. centipeda -ae, a centipede, a worm, called also millepeda or multipeda.
. Chlamydia: N.L. fem. dim. n. from Gr. fem. n. chlamus, a short mantle, a military cloak.
. Coenonia: N.L. fem. n. from Gr. fem. n. coenonia, community, association.
. Daeguia: N.L. fem. n. Daeguia, pertaining to Daegu.
. Dokdonella: N.L. fem. n. Dokdonella, named after Dokdo.
. Dokdonia: N.L. dim. fem. n. Dokdonia, named after Dokdo.
. Donghaeana: N.L. fem. n. Donghaeana, named after Donghae, the Korean name of the East Sea in Korea.
. Faenia: L. fem. (sic) pl. (sic) n. Faenia (sic), hays, a genus of prokaryotes associated with hay.
According to Kurup and Agre, the genus name Faenia is a Latin feminine plural name (sic)! However, according to Rule 10a, the name of a genus must be a substantive, or an adjective used as a substantive, in the singular number. Moreover, the Latin noun faenum is in the neuter gender and the plural nominative must be faena (without i).
. Formosa: N.L. fem. substantive from L. fem. adj. formosa, finely formed, beautiful, handsome.
. Gelria: N.L. fem. n. Gelria, referring to Gelre, one of the 12 provinces of The Netherland.
. Gemella: N.L. fem. substantive from L. fem. adj. gemella, twin, double.
. Georgenia: N.L. fem. n. Georgenia, referring to the village St Georgen in Styria.
. Hafnia: N.L. fem. n. from the old name of Copenhagen.
. Legionella: N.L. fem. dim. n. (from L. fem. n. legio, legion, army), a small legion or army.
. Lonepinella: N.L. fem. dim. n. derived from Lone Pine Koala Sanctuary.
. Massilia: L. fem. n. Massilia -ae, Marseille.
. Mitsuaria: L. suff. -arius -a -um, suffix meaning belonging to; N.L. fem. n. Mitsuaria, belonging to Matsue City.
. Nautilia: N.L. fem. n. from Nautile, the name of a French submersible.
. Nereida (= Nereis): L. fem. n. Nereida, a Nereid, a sea nymph.
. Nevskia: N.L. fem. n. Nevskia, referring to Neva, a river in Leningrad.
. Oligella: N.L. fem. dim. n. (from Gr. adj. oligos, little, small), referring to small prokaryote with limited nutritional properties.
. Orientia: N.L. fem. n. from L. n. oriens, the Orient.
. Pantoea: N.L. fem. substantive from Gr. adj. pantoios, of all sorts or kinds or sources, manifold.
. Pirella: N.L. fem. dim. n. (from L. neut. n. pirum, a pear), a small pear.
. Pirellula: N.L. fem. dim. n. (from N.L. fem. dim. n. pirella, a small pear), a very small pear.
. Pragia: N.L. fem. n. Pragia, referring to Prague.
. Reinekea: N.L. fem. substantive derived from Reineke, geographical name of Reineke Island.
. Rickettsiella: N.L. fem. dim. n. (from N.L. fem. n. Rickettsia, a genus of parasitic prokaryotes), a small Rickettsia.
. Runella: N.L. fem. dim. n. (from English noun rune, an ancient alphabet), that which ressembles figures of the runic alphabet.
. Sagittula: L. fem. dim. n. sagittula -ae, a little arrow.
. Sarcina: L. fem. n. sarcina -ae, a package.
. Sejongia: N.L. fem. n. Sejongia, named after the King Sejong Station.
. Serpens: L. fem. n. serpens -tis, a snake.
. Stella: L. fem. n. stella -ae, a star.
. Stigmatella: N.L. fem. dim. n. (from L. n. stigma, a mark burned in, a brand impressed upon slaves or others, as a mark of disgrace), a small brand or mark.
. Tateyamaria: N.L. fem. n. Tateyamaria, belonging to Tateyama City.
. Turicella: N.L. fem. dim. n. (from L. n. Turicum, the Latin name of Zürich, Switzerland), pertaining to Turicum.
. Woodsholea: N.L. fem. n. named in honour of the Woods Hole Oceanographic Institution, Massachusetts, USA.
. Xylella: N.L. fem. dim. n. (from Gr. neut. n. xulon, piece of wood), a small piece of wood.

. Balnearium: N.L. neut. n. from L. adj. balnearius -a -um, of or pertaining to a bath.
. Chromatium: N.L. neut. n. from Gr. neut. n. chroma -atos, a color, paint.
. Clostridium: N.L. neut. dim. n. (from Gr. n. klôstêr, a spindle), a small spindle.
The L. neut. suffix -ium is sometimes used in bacteriology as a diminutive. However, in Latin, the suffix -ium is generally used to denote a passive quality, a characteristic.
. Crinalium: N.L. neut. dim. n. (from L. adj. crinalis, of hair), a small ?
The L. neut. suffix -ium is sometimes used in bacteriology as a diminutive. However, in Latin, the suffix -ium is generally used to denote a passive quality, a characteristic.
. Lyticum: N.L. neut. substantive from Gr. adj. lutikos: able to loose, able to dissolve.
. Spirillum: N.L. neut. dimin. n. spirillum, a small spiral.

. -acidovorax: N.L. masc. n. Acidovorax, a bacterial genus name.
. -adaptatus: N.L. masc. substantive from L. masc. part. adj. adaptatus, adapted to a thing.
. -alcaligenes: N.L. masc. n. Alcaligenes, a bacterial genus name.
. -amator: L. masc. n. amator -oris, a lover, a friend.
. -amorphus: N.L. masc. substantive from Gr. masc. adj. amorphos, without form, shapeless.
. -arculus: N.L. masc. n. arculus, a small bow.
. -arcus: L. masc. n. arcus -us, a bow.
. -ateles: N.L. masc. substantive from Gr. adj. atelês, without end, incomplete, unfinished, imperfect.
. -avidus: N.L. masc. substantive from L. masc. adj. avidus, vehemently desiring, longing for.
. -bacillus: L. masc. n. bacillus -i, a small staff.
. -bacter: N.L. masc. n. bacter, a rod, bacterium, prokaryote; see: Judicial Opinion n° 3.
. -bius: N.L. masc. n. from Gr. masc. n. bios, life.
. -blastus: N.L. masc. n. from Gr. masc. n. blastos, a shoot, bud shoot.
. -borus: N.L. masc. substantive or adj. from Gr. adj. boros, gluttonous.
. -botulus: L. masc. n. botulus -i, an intestine, a sausage.
. -bulbus: L. masc. n. bulbus -i, onion.
. -calculus: L. masc. n. calculus -i, a small stone, pebble.
. -caldus: N.L. masc. substantive from L. masc. adj. caldus, warm, hot.
. -calyx: N.L. masc. n. from Gr. masc. n. kalux, the bud, cup, or calyx of a flower.
. -caulis: L. masc. n. caulis -is, a stalk, stem of a plant.
. -clasticus: N.L. masc. substantive from Gr. adj. klastos, broken in pieces + L. masc. suff. -icus.
. -coccus: N.L. masc. n. from Gr. masc. n. kokkos, a grain, seed.
. -cola: L. masc. (or fem.) abbreviation of L. masc. (or fem.) n. incola -ae, an inhabitant.
. -comes: L. masc. n. comes, a companion.
. -crinis: L. masc. n. crinis -is, hair.
. -culleus: L. masc. n. culleus -i, a leather bag, a sack for holding liquids.
. -cumulans: L. part. adj. cumulans, accumulating.
. -curvus: N.L. masc. substantive from L. masc. adj. curvus, crooked, curved, bent.
. -cyclus: L. masc. n. cyclus -i, a circle or a cycle, recurring period.
. -desulfatator: N.L. masc. n. desulfatator, sulfate-reducer.
. -discus: L. masc. n. discus -i, a disc.
. -factor: L. masc. n. factor -oris, a maker.
. -fer: N.L. masc. suff. from L. v. fero, to bear, produce.
. -ferax: N.L. masc. substantive from L. masc. adj. ferax, fruitful, fertile, prolific.
. -fex: N.L. masc. suff. from L. v. facio, to make.
. -flexus: L. masc. n. flexus -us, a bending, turning.
. -follis: L. masc. n. follis -is, a leather bag.
. -fractor: L. masc. n. fractor, a breaker.
. -fustis: L. masc. n. fustis -is, a stick, staff, cudgel, club.
. -genes: N.L. masc. suff. from Gr. v. gennaô, to produce, engender.
. -ger: N.L. masc. suff. from L. v. gero, to carry, bear.
. -globus: L. masc. n. globus -i, a round ball, globe, sphere.
. -habitans: L. masc. part. adj. habitans, inhabiting.
. -hopalus: N.L. masc. n. from Gr. masc. n. hopallios, opal (in Latin an opal = opalus).
. -humus: L. masc. n. humus, soil.
. -icanus: N.L. masc. substantive from Gr. adj. hikanos, capable, sufficient, adequate.
. -ianus: L. masc. n. Ianus or Janus, an old Italian deity, represented with two faces looking in opposite directions.
. -incola: L. masc. (or fem.) n. incola -ae, an inhabitant.
. -indiges: N.L. masc. substantive from L. adj. indiges, needy.
. -kineococcus: N.L. masc. n. Kineococcus, name of a genus.
. -labrys: N.L. masc. n. Labrys, name of a genus.
. -liparus: N.L. masc. n. from. Gr. adj. liparos, oily, fat, fatty, greasy.
. -lituus: L. masc. n. lituus, an augur's crook or crosier, a curved trumpet, a crook.
. -lobus: L. masc. n. lobus -i, a lobe.
. -lunatus: N.L. masc. substantive from L. masc. part. adj. lunatus, half-moon-shaped, bent into a crescent.
. -marinus: N.L. masc. substantive from L. masc. adj. marinus, of the sea, marine.
. -murus: L. masc. n. murus -i, a wall, city wall.
. -myces: N.L. masc. n. from Gr. masc. n. mukês -etis, a mushroom, any thing shaped like a mushroom.
. -nauticus: N.L. masc. substantive from L. adj. nauticus -a -um, of a sailor, nautical.
. -nexus: L. masc. n. nexus -us, a binding, tying together, entwining, connecting, a coil (?).
. -oides: L. masc. suff. -oides, from Gr. suff. eides (from Gr. n. eidos, that which is seen, form, shape, figure), ressembling, similar.
. -bacteroides: N.L. masc. n. Bacteroides, name of a genus.
. -pedobacter: N.L. masc. n. Pedobacter, name of a genus.
. -phagus: N.L. masc. n. from Gr. masc. n. phagos, glutton or N.L. masc. substantive from Gr. v. phagein, to eat.
. -philus: N.L. masc. n. from Gr. masc. n. philos, friend or N.L. masc. substantive from Gr. masc. adj. philos, loving.
. -phonus: N.L. masc. n. from Gr. masc. n. phonos, murder, slaughter.
. -piger: N.L. masc. n. from L. masc. adj. piger, lazy, slow, sluggish.
. -planes: N.L. masc. n. from Gr. masc. n. planês, a wanderer, vagabond (warning: the L. masc. n. planes -etis means a wandering star, planet).
. -planus: N.L. masc. substantive from L. masc. adj. planus, flat.
. -proteus: L. masc. n. Proteus -i, a prophet and god of the sea.
. -pulveratus: L. masc. part. adj. pulveratus, bestrewed with dust.
. -pyrus: N.L. masc. (!) n. from Gr. neut. n. pur, a fire.
. -reductor: N.L. masc. n. reductor (very rare in classical Latin) one who leads or brings back.
. -ramibacter: N.L. masc. n. Ramibacter, name of a genus.
. -ramulus: L. masc. n. ramulus, a small branch.
. -rhodobacter: N.L. masc. n. Rhodobacter, name of a genus.
. -rubrobacter: N.L. masc. n. Rubrobacter, name of a genus.
. -ruptor: L. masc. n. ruptor -oris, a breaker, violator.
. -salinus: N.L. masc. substantive from N.L. masc. adj. salinus, saline.
. -segetibacter: N.L. masc. n. Segetibacter, name of a genus.
. -serpens: L. masc. n. serpens -tis, a snake.
. -sinus: L. masc. n. sinus -us, a bending, curve fold.
. -sipho or -siphon: L. masc. n. sipho -onis or siphon -onis, a siphon, a kind of fireengine, a little pipe.
. -stipes: L. masc. n. stipes -itis, a log, stump, trunk of a tree, a branch.
. -streptococcus: N.L. masc. n. Streptococcus, name of a genus.
. -teichus: N.L. masc. (!) n. from Gr. neut. n. teichos, a wall.
. -teredinibacter: N.L. masc. n. teredinibacter, name of a bacterial genus.
. -thermus: N.L. masc. substantive from Gr. adj. thermos, hot.
. -tilus: N.L. masc. n. from Gr. masc. n. tilos, anything plucked.
. -torris: L. masc. n. torris -is, fire.
. -truncus: L. masc. n. truncus -i, stick.
. -tutus: N.L. masc. substantive from L. masc. adj. tutus, protected.
. -uncus: L. masc. n. uncus -i, a hook.
. -varius: N.L. masc. substantive from L. masc. adj. varius, manifold, diversified, various, diverse.
. -vermiculus: L. masc. n. vermiculus, a little worm.
. -vibrio: N.L. masc. n. vibrio, that which moves rapidly, that which vibrates from L. v. vibro to move rapidly to and fro, to vibrate; or N.L. masc. n. Vibrio, name of a genus.
. -vivax: N.L. masc. substantive from L. masc. adj. vivax, long-lived, tenacious of life, lasting, enduring.
. -vorans: N.L. masc. substantive from L. part. adj. vorans, devouring.
. -vorax: N.L. masc. substantive from L. masc. adj. vorax, gluttonous, voracious.
. -vorus: N.L. masc. substantive from N.L. masc. adj. vorus, consuming.

. -(a)na: L. fem. suffix used to indicate the geographical origin (for example, Salana, referring to the River Saale in Germany).
. -arcula: L. fem. n. arcula -ae, a small chest or box, a casket.
. -aria: L. fem. suffix meaning belonging to.
. -asaia: N.L. fem. n. Asia, name of a genus.
. -ata: N.L. fem. ending ata, of or pertaining to.
. -baca or -bacca: L. fem. n. baca -ae or bacca -ae, a berry, especially the fruit of the olive.
. -bacula: L. fem. n. bacula -ae, a small berry.
. -bartonella: N.L. fem. n. Bartonella, name of a genus.
. -bifida: N.L. fem. substantive from L. fem. adj. bifida, split into two parts.
. -branca: L. fem. n. branca -ae, a claw, pax, the root of the English word branch.
. -capsa: L. fem. n. capsa -ae, a box.
. -catella: L. fem. n. catella -ae, a small chain.
. -cauda: L. fem. n. cauda -ae, the tail of an animal.
. -cella: L. fem. n. cella -ae, a room.
. -chaeta: N.L. fem. n. from Gr. fem. n. chaitê, long, flowing hair.
. -chlamydia: N.L. fem. n. Chlamydia, name of a genus.
. -chloris: N.L. fem. substantive from Gr. fem. adj. chlora, green.
. -cista: L. fem. n. cista -ae, a chest, box.
. -clava: L. fem. n. clava -ae, stick, staff, cudgel, club.
. -cola: L. fem. (or masc.) abbreviation of L. fem. (or masc.) n. incola -ae, an inhabitant.
. -coniux: L. fem (or masc.) n. coniux, a married person, consort, spouse, husband, wife.
. -corallia: N.L. fem. (!) n. from Gr. neut. n. korallion, coral or from L. neut. n. corallium, coral.
. -curvata: N.L. fem. substantive from L. fem. part. adj. curvata, curved.
. -cytophaga: N.L. fem. n. Cytophaga, name of a bacterial genus.
. -cystis: N.L. fem. n. from Gr. fem. n. kustis, the bladder.
. -derma: N.L. fem. (!) n. from Gr. neut. n. derma, skin.
. -ella: N.L. fem. dim. ending -ella.
. -eggerthella: N.L. fem. n. Eggerthella, name of a genus.
. -eryma: N.L. fem. (!) n. from Gr. neut. n. eruma, a fence, barrier, guard.
. -faba: L. fem. n. faba -ae, a bean.
. -ferax: N.L. fem. substantive from L. fem. adj. ferax, fruitful, fertile, prolific.
. -ferrimonas: N.L. fem. n. Ferrimonas, a bacterial genus name.
. -ferula: L. fem. n. ferula -ae, a stick, cane.
. -forma: L. fem. n. forma -ae, form (in the most comprehensive sense of the word), contour, figure, shape, appearance.
. -glaeba: L. fem. n. glaeba, clump, crumb, aggregate.
. -gloea: N.L. fem. n. from Gr. fem. n. gloia, glue.
. -gulbenkiania: N.L. fem. n. gulbenkiania, name of a genus.
. -ia: L. fem. suffix sometimes used in bacteriology as a diminutive (for example, Chlamydia: N.L. fem. dim. n. from Gr. fem. n. chlamus, a short mantle, a military cloak) or to denote a locality (for example, Beutenbergia, referring to Beutenberg; Budvicia, referring to Budvicium, the Latin name of the city Ceské Budejovice; Gelria, referring to Gelre, one of the 12 provinces of The Netherland; Georgenia, referring to the village St Georgen in Styria; Pragia, referring to Prague...).
. -ichthya: N.L. fem. (!) n. from Gr. masc. n. ichthus, a fish.
. -ina: L. fem. suff. -ina, belonging to.
. -incola: L. fem. (or masc.) n. incola -ae, an inhabitant.
. -kutzneria: N.L. fem. n. Kutzneria, name of a genus.
. -labilia: N.L. fem. substantive from L. fem. adj. labilis, lipping, gliding, prone to slip or slide.
. -lacinia: L. fem. n. lacinia -ae, the lappet, flap, edge.
. -linea: L. fem. n. linea -ae, a linen thread, a string, line.
. -luna: L. fem. n. luna -ae, the moon, a crescent-shaped ornament.
. -madura: N.L. fem. n. from Madura, the name of a province in India.
. -margarita: L. fem. n. margarita -ae, a pearl.
. -marina: L. fem. substantive from L. fem. adj. marina, of the sea, marine.
. -melia: N.L. fem. n. from Gr. fem. n. Meliai, a race of nymphs said to have sprung from the spot of earth on which fell the blood of Uranus.
. -monas: N.L. fem. n. from Gr. fem. n. monas, a unit.
. -moritella: N.L. fem. n. Moritella, name of a genus.
. -morpha: N.L. fem. n. from Gr. fem. n. morphê, form, shape.
. -musa: N.L. fem. n. musa -ae, a banana.
. -myxa: N.L. fem. n. from Gr. fem. n. muxa, slime, mucus.
. -na: see, (a)na.
. -nocardia: N.L. fem. n. Nocardia, name of a genus.
. -nocardiopsis: N.L. fem. n. Nocardiopsis, name of a genus.
. -nutrix: L. fem. n. nutrix -icis, she who nourishes or maintains a thing, a nurse.
. -oerskovia: N.L. fem. n. Oerskovia, name of a genus.
. -oides: L. fem. suff. -oides, from Gr. suff. eides (from Gr. n. eidos, that which is seen, form, shape, figure), ressembling, similar.
. -opsis: N.L. fem. n. from Gr. fem. n. opsis, appearance.
. -oscilla: N.L. fem. (!) n. from L. neut. n. oscillum, a swing.
. -pedia: N.L. fem. n. from Gr. fem. n. pedias, a plain.
. -perlucidibaca: N.L. fem. n. Perlucidibaca, name of a genus.
. -phaga: N.L. fem. substantive from Gr. v. phagein, to eat.
. -phila: N.L. fem. n. from Gr. fem. n. philê, friend or N.L. fem. substantive from Gr. fem. adj. philê, loving.
. -pila: L. fem. n. pila -ae, a ball.
. -pirellula: N.L. fem. n. Pirellula, name of a prokaryotic genus.
. -plana: N.L. fem. n. from Gr. fem. n. planê, a wandering, roaming.
. -planes: N.L. fem. (!) n. from Gr. masc. n. planês, a wanderer, vagabond.
. -ploca: N.L. fem. n. from Gr. fem. n. plokê, a twining, braid, twist.
. -prevotella: N.L. fem. n. Prevotella, name of a genus.
. -pruina: L. fem. n. pruina -ae, hoar-frost, rime.
. -pyxis: N.L. fem. n. from Gr. n. puxis, a box.
. -regula: L. fem. n. regula -ae, a straight piece of wood, ruler, rule.
. -restis: L. fem. n. restis -is, a rope, cord.
. -rhabdus: N.L. fem. n. from Gr. fem. n. rhabdos, a rod, wand.
. -rickettsia: N.L. fem. n.Rickettsia, name of a genus.
. -ruegeria: N.L. fem. n. Ruegeria, name of a genus.
. -saeta: L. fem. n. saeta -ae, a thick, stiff hair.
. -sarcina: L. fem. n. sarcina -ae, a package.
. -scardovia: N.L. fem. n. Scardovia, name of a genus.
. -serpentilla: N.L. fem. n. serpentilla, a small snake.
. -shewanella: N.L. fem. n. Shewanella, name of a genus.
. -sphaera: L. fem. n. sphaera -ae, a globe, sphere.
. -sphaerula: L. fem. n. sphaerula, a small sphere
. -spica: L. fem. n. spica -ae, a spike, a tuft.
. -spina: L. fem. n. spina -ae, a thorn.
. -spira: L. fem. n. spira -ae, a coil of a snake, coil, spire, that which is wound, wreathed, coiled, or twisted.
. -spirulina: N.L. fem. dim. n., a small coil from L. fem. n. spirula -ae, a coil.
. -sporia (sic, spelling error): N.L. fem. n. from Gr. fem. n. spora, a seed.
. -spora: N.L. fem. n. from Gr. fem. n. spora, a seed.
. -sporosarcina: N.L. fem. n. Sporosarcina, name of a genus.
. -stega: N.L. fem. n. from Gr. fem. n. stegê, roof, chamber, room, house.
. -sutterella: N.L. fem. n. Sutterella, name of a genus.
. -syntropha: N.L. fem. n. from Gr. fem. n. suntrophê, foster-sister.
. -talea: L. fem. n. talea -ae, a slender staff, rod, stick, stake, bar.
. -tenera: N.L. fem. substantive from L. fem. adj. tenera, delicate
. -tepida: N.L. fem. substantive from L. fem. adj. tepida, moderately warm, lukewarm, tepid.
. -terricola: L. fem. n. terricola, a dweller upon earth, a terrestrial.
. -terrigena: L. fem. substantive from L. fem. adj. terrigena, born from the earth.
. -toga: L. fem. n. toga -ae, a covering, garment.
. -tomix: L. fem. n. tomix (or thomix) -icis, a string or thread.
. -thrix: N.L. fem. n. from Gr. fem. n. thrix, hair.
. -trichia: N.L. fem. n. from Gr. fem. n. thrix trichos, hair.
. -tropha: N.L. fem. n. from Gr. n. fem. trophê, nourishment, food.
. -trophia: N.L. fem. n. from Gr. n. fem. trophê, nourishment, food.
. -ula: N.L. fem. dim. ending -ula.
. -vallis: L. fem. n. vallis -is, a vale, valley.
. -virga: L. fem. n. virga -ae, a green twig, small rod.
. -virgula: L. fem. n. virgula -ae, a little twig, a small rod, a wand.
. -vita: L. fem. n. vita -ae, life.
. -vorans: N.L. fem. substantive from L. part. adj. vorans, devouring.
. -vorax: N.L. fem. substantive from L. fem. adj. vorax, gluttonous, voracious.
. -xanthomonas: N.L. fem. n. Xantomonas, name of a genus.
. -zobellia: N.L. fem. n. Zobellia, name of a genus.

. -acinum: L. neut. n. acinum -i, a berry, esp. the grape, the stone of a berry.
. -actinosynnema: N.L. neut. n. Actinosynnema, a bacterial generic name.
. -angium: L. neut. n. from Gr. neut. n. angeion, vessel for holding liquid or dry substances; of the human or animal body, vessel, cavity.
. -archaeum: N.L. neut. n. archaeum (from Gr. adj. archaios, ancient), archaeon.
. -bacillum: L. neut. n. bacillum -i, a small staff.
. -bacterium: L. neut. n. bacterium -i, a stick, staff.
. -bactrum: N.L. neut. n. from Gr. neut. n. baktron, a stick, cudge.
. -baculum: L. neut. n. baculum -i, a stick, staff.
. -bium: N.L. neut. (!) n. from Gr. masc. n. bios, life.
. -brachium: L. neut. n. brachium -i or bracchium -i, the arm.
. -chromatium: N.L. neut. n. from Gr. neut. n. chroma, a color, paint.
. -caldum: N.L. neut. substantive from L. neut. adj. caldum, warm, hot.
. -chloron: N.L. neut. substantive from Gr. neut. adj. chloron, green.
. -citreum: L. neut. n. citreum, lemon.
. -cladium: N.L. neut. (!) n. cladium from Gr. masc. n. klados, a branch, shoot of a tree.
. -clasticum: N.L. neut. substantive from Gr. neut. adj. klaston, broken in pieces.
. -corpusculum: L. neut. n. corpusculum -i, a little body.
. -crispum: N.L. neut. substantive from L. neut. part. adj. crispum, tightly curled.
. -curvum: N.L. neut. substantive from L. neut. adj. curvum, curved.
. -dictyon: N.L. neut. n. from Gr. neut. n. diktuon, a net.
. -dictium: N.L. neut. n. from Gr. neut. n. diktuon, a net.
. -ellum: L. neut. dim. ending -ellum.
. -ferax: N.L. neut. substantive from L. neut. adj. ferax, fruitful, fertile, prolific.
. -fermentans: N.L. neut. substantive from L. neut. part. adj. fermentans, fermenting.
. -filamentum: L. neut. n. filamentum -i, an assembling of threads.
. -filum: L. neut. n. filum -i, a thread.
. -flexile: N.L. neut. substantive from L. neut. part. adj. flexile, pliant, pliable, flexible.
. -flexum: N.L. neut. substantive from L. neut. adj. flexum, bent, winding.
. -frigus: L. neut. n. frigus -oris: cold, coolness, coldness.
. -genens: N.L. neut. substantive from L. part. neut. adj. genens, producing.
. -generans: N.L. neut. substantive from L. part. neut. adj. generans, producing.
. -genium: N.L. neut. suff. from Gr. v. gennaô, to produce, engender.
. -geometricum: N.L. neut. substantive from L. neut. adj. geometricum, of or belonging to geometry, geometrical.
. -glomus: L. neut. n. glomus -eris, a ball or clue of yarn, thread, etc..
. -granulum: L. neut. n. granulum -i, a small grain.
. -granum: L. neut. n. granum -i, a grain, seed, small kernel.
. -herpeton: N.L. neut. n. from Gr. neut. n. herpeton, beast or animal which goes on all fours, a creeping thing, reptile.
. -ium: L. neut. suffix sometimes used in bacteriology as a diminutive (for example, Clostridium: N.L. neut. dim. n. from Gr. n. klôstêr, a spindle; Crinalium: N.L. neut. dim. n. from L. adj. crinalis, of hair). However, in Latin, the suffix -ium is generally used to denote a passive quality, a characteristic.
. -lyticum: N.L. neut. substantive from Gr. adj. lutikos: able to loose, able to dissolve.
. -microbium: N.L. neut. n. microbium, microbe.
. -monile: L. neut. n. monile -is, a necklace, collar.
. -natrum: N.L. neut. n. natrum, from N.L. n. natron, arbitrarily derived from the Arabic n. natrun or natron soda
. -nema: N.L. neut. n. from Gr. neut. n. nêma -atos, that which is spun, thread, yarn.
. -nostoc: N.L. neut. n. Nostoc, algal generic name.
. -num: L. neut. suff. to denote a matter.
. -oides: L. neut. suff. -oides, from Gr. suff. eides (from Gr. n. eidos, that which is seen, form, shape, figure), ressembling, similar.
. -oscillum: L. neut. n. oscillum, a swing.
. -ovulum: N.L. neut. dim. n. ovulum, a small egg from L. neut. n. ovum -i, an egg.
. -ovum: L. neut. n. ovum -i, an egg.
. -phanon: N.L. neut. substantive from Gr. neut. adj. phanon, light, bright.
. -philum: N.L. neut. substantive from Gr. neut. adj. philon, loving.
. -plasma: N.L. neut. n. from Gr. neut. n. plasma, anything formed or moulded, image, figure.
. -profundum: L neut n profundum, depth abyss.
. -pyrum: N.L. neut. n. from Gr. neut. n. pur, fire.
. -quadratum: L. neut. n. quadratum, a square.
. -rhabdium: Gr. neut. n. rhabdium, a little rod.
. -rhizobium: N.L. neut. n. Rhizobium, name of a genus.
. -rubrum: N.L. neut. substantive from L. neut. adj. rubrum, red.
. -salsum: N.L. neut. substantive from L. neut. part. adj. salsum, salted, salty.
. -simplex: N.L. neut. substantive from L. neut. adj. simplex, simple, uncomplicated.
. -soma: N.L. neut. n. from Gr. neut. n. soma, body.
. -sphingobacterium: N.L. neut. n. Sphingobacterium, a bacterial genus name.
. -spirillum: N.L. neut. dimin. n. spirillum -i, a small spiral.
. -sporangium: N.L. neut. n. from Gr. fem. n. spora + Gr. neut. n. angeio, a vessel.
. -thalassium: N.L. neut. substantive from Gr. adj. thalassaion, of, in, on or from the sea, belonging to it.
. -tignum: L. neut. n. tignum -i, a piece or stick of timber, a trunk of a tree, a log.
. -tomaculum: L. neut. n. tomaculum -i, a kind of sausage.
. -venabulum: L. neut. n. venabulum -i, a huntingspear.
. -verticillium: N.L. neut.(!) n. from L. masc. n. verticillus, whorl, whirl of a spindle.
. -zoon: N.L. neut. n. from Gr. neut. n. zoon, animal.

. The Latin noun incola (an inhabitant) may be either masculine or feminine. So generic names which end in -incola or -cola (abbreviation of incola) may be in the masculine or in the feminine gender.
For example, Aestuariicola, Alkalilimnicola, Biostraticola, Gallicola, Haloincola, Hwanghaeicola, Marmoricola, Mycetocola, Nitrincola, Pelagicola, Subtercola... are in the masculine gender; Algicola, Echinicola, Glaciecola, Halostagnicola, Litoricola, Marisediminicola, Thermincola ... are in the feminine gender.

. Many other Latin nouns may be either masculine or feminine: advena, alienigena, bos, canis, conviva, dies, exsul (or exul), haeres (or heres), imbrex, lynx, multicolor, myrtus, nasica, parens, rurigena, serpentigena, silvicola, specus, terrigena, umbraticola, unigena, ventricola, verna... However, none of these nouns has been used as the last component of a generic name (-terrigena in Haloterrigena is a feminine adjective).

Last components in compound generic names of masculine or feminine or neuter gender

. The L. part. adj. labens (gliding) used as a substantive may be in the masculine, the feminine or the neuter gender. The part. adj. labens is used in the genus name Nonlabens Lau et al. 2005. The gender is not given by Lau et al. 2005 and the specific epithet of the sole species does not allow the correct gender to be determined.

. The following arbitrary names are in the feminine gender.
. Afipia arbitrarily derived from AFIP (Armed Force Institute of Pathology).
. Basfia arbitrarily derived from BASF SE (a chemical company in Ludwigshafen, Germany)
. Cedecea arbitrarily derived from CDC (Centers for Disease Control).
. Deefgea arbitrarily derived from the acronym DFG for Deutsche Forschungsgemeinschaft (German Science Foundation).
. Demequina arbitrarily derived from demethylmenaquinone.
. Desemzia arbitrarily derived from DSMZ (Deutsche Sammlung von Mikroorganismen und Zellkulturen).
. Emticicia arbitrarily derived from the acronym MTCC (Microbial Type Culture Collection and Gene Bank).
. Iamia arbitrarily derived from the acronym IAM (Institute of Applied Microbiology at the University of Tokyo).
. Kaistella arbitrary derived from KAIST (Korea Advanced Institute of Science and Technology).
. Kaistia arbitrary derived from KAIST (Korea Advanced Institute of Science and Technology).
. Kistimonas arbitrary derived from KIST (Korea Institute of Science and Technology ).
. Kordia arbitrarily derived from KORDI (Korea Ocean Research and Development Institute).
. Kribbella arbitrarily derived from KRIBB (Korean Research Institute of Bioscience and Biotechnology).
. Kribbia arbitrarily derived from KRIBB (Korean Research Institute of Bioscience and Biotechnology).
. Mameliella arbitrarily derived from MME laboratory (Marine microbial ecology laboratory, China).
. Mesonia arbitrarily derived from MES (Marine Experimental Station of the Pacific Institute of Bioorganic Chemistry).
. Niabella arbitrarily derived from NIAB (National Institute of Agricultural Biotechnology).
. Niastella arbitrary derived from NIAST (National Institute of Agricultural Science and Technology).
. Nubsella arbitrary derived from NUBS (Nihon University College of Bioresource Sciences).
. Pibocella arbitrarily derived from PIBOC (Pacific Institute of Bioorganic Chemistry).
. Rikenella arbitrarily derived from RIKEN (Rikagaku Kenkyusho; Institute of Physical and Chemical Research).
. Rudaea arbitrarily derived from RDA (Rural Development Administration).
. Rudanella arbitrarily derived from RDA (Rural Development Administration).
. Sciscionella arbitrarily derived from SCISCIO (South China Sea Institute of Oceanology).
. Stakelama arbitrarily derived from State Key Laboratory of Marine Environment Science.
. Simkania arbitrary name formed from the personal name Simona Kahane.
. Tistrella arbitrarily derived from TISTR (Thailand Institute of Scientific and Technological Reseach).
. Waddlia arbitrarily derived from WADDL (Washington Animal Disease Diagnostic-Laboratory).
. Woodsholea arbitrary name formed from the Woods Hole Oceanographic Institution, Massachusetts, USA.
. Yimella arbitrarily derived from YIM (Yunnan Institute of Microbiology).
. Yokenella arbitrarily derived from Kokuritsu-yoboueisei-kenkyusho (National Institute of Disease Prevention and Health).

. Synergistes (arbitrarily derived from English n. synergist), Methermicoccus (arbitrary name referring to a small, thermophilic, methane-producing coccus), and Cesiribacter (arbitrarily derived for CSIR, Council of Scientific and Industrial Research are in the masculine gender.

1) Generic names assigned to the masculine gender:
. Methanopyrus is in the masculine gender. However, the Greek noun pur (a fire) is in the neuter gender.
. The generic names which end in -teichus are in the masculine gender. However, the Greek noun teichos (a wall of a city) is in the neuter gender. The Greek masculine noun meaning a wall (of a house) is toichos.

2) Generic names assigned to the feminine gender:
. Actinocorallia is in the feminine gender. However, the Greek noun korallion (coral) or the Latin noun corallium (coral) are in the neuter gender.
. Bactoderma is in the feminine gender. However, the Greek noun derma (skin) is in the neuter gender.
. Faenia: According to Kurup and Agre, the genus name Faenia is a Latin feminine plural name (sic)! However, according to Rule 10a, the name of a genus must be a substantive, or an adjective used as a substantive, in the singular number. Moreover, the Latin noun faenum is in the neuter gender and the plural nominative must be faena (without i).
. Spirilliplanes is in the feminine gender. However, the Greek noun planês (a wanderer, vagabond) is in the masculine gender.
. Tropheryma is in the feminine gender. However, the Greek noun eruma (a fence, barrier, guard) is in the neuter gender.
. The generic names which end in -oscilla are in the feminine gender. However, the Latin noun oscillum (a swing) is in the neuter gender.
. Sporichthya is in the feminine gender. However, the Greek noun ichthus (a fish) is in the masculine gender.

3) Generic names assigned to the neuter gender:
. Ancalochloris is in the neuter gender. However, the N.L. subtantive chloris (from Gr. adj. chloros, green) should be in the masculine or in the feminine gender.
. The generic names which end in -bium are in the neuter gender. However, the Greek noun bios (life) is in the masculine gender.
The generic names which end in -microbium, may be considered to be correctly assigned to the neuter gender (N.L. neut. n. microbium, microbe).
. Thermocladium is in the neuter gender. However, the Greek noun klados (a branch, shoot of a tree) is in the masculine gender.
. Streptoverticillium is in the neuter gender. However, the Latin noun verticillus (whorl, whirl of a spindle) is in the masculine gender.

Generic names in the masculine gender

Generic names in the feminine gender

Generic names in the neuter gender

Agarivorans: The gender of the genus name is not provided in the paper by Kurahashi and Yokota 2004. However, the epithet of the type species (albus) is in the masculine gender and Agarivorans must be in the masculine gender.

Bacteriovorax: The gender is not given by Baer et al. 2000. According to Rule 65(1) when the original author failed to indicate the gender, a subsequent author has the right of choice. In 2004, Baer et al. propose the species Bacteriovorax litoralis and Bacteriovorax marinus. The epithets litoralis and marinus are in the masculine gender. Clearly, Baer et al. 2004 choosed the masculine gender for the genus name Bacteriovorax.

Citricoccus: The gender is not given by Altenburger et al. 2002. However, according to Rule 65, Citricoccus should be in the masculine gender.

Dialister: The etymology, and therefore the gender, of the genus name Dialister is unknown. According to Rule 65(3), Downes et al. 2003 propose that Dialister be in masculine gender.

Diaphorobacter

Dichelobacter

Dinoroseobacter

Diplocalyx: The gender is not given by Bermudes et al. 1988. However, according to Rule 65, Diplocalyx should be in the masculine gender.

Gilvimarinus: The gender is not given Du et al. 2009. However, according to Rule 65, the name Gilvimarinus should be in the masculine gender.

Glaciibacter

Gluconacetobacter

Gluconobacter

Glycomyces: The gender is not given by Labeda et al. 1985. However, according to Rule 65, Glycomyces should be in the masculine gender.

Meniscus: The gender is not given by Irgens 1977. However, according to Rule 65, Meniscus should be in the masculine gender.

Methanofollis: The gender is not given by Zellner et al. 1999. However, according to Rule 65, Methanofollis should be in the masculine gender.

Methanohalophilus

Methanolobus

Methanoplanus

Methanopyrus: Methanopyrus is assigned to the masculine gender. However, the Greek noun pur (a fire) is in the neuter gender.

Methylovorus: The gender is not given by Govorukhina and Trotsenko 1991. However, Methylovorus seems in the masculine gender because the specific epithet glucosotrophus is in the masculine gender.

Psychroserpens: The gender is not given by Bowman et al. 1997. The latin noun serpens can be in the masculine or in the feminine gender. The specific epithet of the species proposed by Bowman et al. 1997 does not allow the correct gender to be determined. According to Rule 65(1) when the original authors failed to indicate the gender, a subsequent author has the right of choice. In 2006, Kwon et al. propose the species Psychroserpens mesophilus (N.L. masculine adjective). Clearly, Kwon et al. 2006 choosed the masculine gender for the genus name Psychroserpens.

Selenihalanaerobacter

Thermicanus: The gender is not given by Gößner et al. 2000. However, according to Rule 65, Thermicanus should be in the masculine gender.

Actinocorallia: The gender is not given by Iinuma et al. 1994 but Actinocorallia seems in the feminine gender because the specific epithets, treated as adjectives, are in the feminine gender (see aurantiaca, glomerata, herbida, libanotica, longicatena). However, the Greek noun korallion (coral) or the Latin noun corallium (coral) are in the neuter gender.

Allocatelliglobosispora

Aquimarina: The gender of the genus Aquimarina is not provided in the article by Nedashkovskaya et al. 2005. According to Rule 65(2) Aquimarina must be in the feminine gender.

Bactoderma: Bactoderma is assigned to the feminine gender. However, the Greek noun derma (skin) is in the neuter gender.

Faenia: According to Kurup and Agre, the genus name Faenia is a Latin feminine plural name (sic)! However, according to Rule 10a, the name of a genus must be a substantive, or an adjective used as a substantive, in the singular number. Moreover, the Latin noun faenum is in the neuter gender and the plural nominative must be faena (without i).

Hallella
Haloactinopolyspora

Limnothrix (not validly published)

Methanomethylovorans: The gender of the generic name is not provided in the effective publication by Lomans et al. 1999. However, the specific epithet hollandica is an adjective in the feminine gender and Methanomethylovorans must be in the feminine gender.

Methylocystis: The correct gender of the genus name, feminine gender (not masculine gender as cited by Bowman et al. 1993), was provided by Dedysh et al. 2007.

Microcystis (not validly published)

Microscilla: Microscilla is assigned to the the feminine gender. However, the Latin noun oscillum (a swing) is in the neuter gender.

Planktothrix (not validly published)

Propioniferax: The gender is not given by Yokota et al. 1994. However, Propioniferax seems in the feminine gender because the specific epithet innocua is in the feminine gender.

Spirilliplanes: Spirilliplanes is assigned to the feminine gender. However, the Greek noun planês (a wanderer, vagabond) is in the masculine gender.

Spirillospora

Spirochaeta

Spongiispira

Sporichthya: Sporichthya isassigned to the feminine gender. However, the Greek noun ichthus (a fish) is in the masculine gender.

Tropheryma: Tropheryma is assigned to the feminine gender. However, the Greek noun eruma (a fence, barrier, guard) is in the neuter gender.

Vitreoscilla: Vitreoscilla is assigned to the the feminine gender. However, the Latin noun oscillum (a swing) is in the neuter gender.

Acetoanaerobium: Acetoanaerobium is assigned to the neuter gender. However, the Greek noun bios (life) is in the masculine gender.

Acetobacterium

Acetofilamentum

Acetogenium

Acetohalobium: Acetohalobium is assigned to the neuter gender. However, the Greek noun bios (life) is in the masculine gender.

Aeropyrum: According to Rule 65(2), the genus name Aeropyrum must be in the neuter gender, not in the masculine gender as cited in the paper by Sako et al. 1996.

Aestuariimicrobium

Agrobacterium

Albidovulum

Alkalibacterium
Alkalibaculum

Allorhizobium: Allorhizobium is assigned to the neuter gender. However, the Greek noun bios (life) is in the masculine gender.

Ancalochloris: The etymology is Gr. masc. n. ancalos, arm; Gr. adj. chloros, green; N.L. neut. n. Ancalochloris, arm (-producing) green (microbe). According to rules of Latin and latinization Ancalochloris should be in the masculine or in the feminine gender.

Atopobium: Atopobium is assigned to the neuter gender. However, the Greek noun bios (life) is in the masculine gender.

Aureobacterium

Avibacterium

Azorhizobium: Azorhizobium is assigned to the neuter gender. However, the Greek noun bios (life) is in the masculine gender.

Azospirillum

Bacteriolyticum (illegitimate)

Bradyrhizobium: Bradyrhizobium is assigned to the neuter gender. However, the Greek noun bios (life) is in the masculine gender.

Chlorobium: Chlorobium is assigned to the neuter gender. However, the Greek noun bios (life) is in the masculine gender.

Crinalium (not validly published)

Desulfohalobium: Desulfohalobium is assigned to the neuter gender. However, the Greek noun bios (life) is in the masculine gender.

Gallibacterium
Geomicrobium

Halanaerobaculum

Halanaerobium: Halanaerobium is assigned to the neuter gender. However, the Greek noun bios (life) is in the masculine gender.

Hydrogenoanaerobacterium

Mesorhizobium: Mesorhizobium is assigned to the neuter gender. However, the Greek noun bios (life) is in the masculine gender.

Methanohalobium: Methanohalobium is assigned to the neuter gender. However, the Greek noun bios (life) is in the masculine gender.

Methanomicrobium

Methanosalsum

Methanospirillum

Methylibium: Methylibium is assigned to the neuter gender. However, the Greek noun bios (life) is in the masculine gender.

Myceligenerans: The gender is not given by Cui et al. 2004. However, Myceligenerans must be in the neuter gender because the specific epithet of the type species, Myceligenerans xiligouense, is in the neuter gender.

Novosphingobium: Novosphingobium is assigned to the neuter gender. However, the Greek noun bios (life) is in the masculine gender.

Phascolarctobacterium

Pseudosphingobacterium

Rhizobium: Rhizobium is assigned to the neuter gender. However, the Greek noun bios (life) is in the masculine gender.

Rhizomicrobium

Rhodobium: Rhodobium is assigned to the neuter gender. However, the Greek noun bios (life) is in the masculine gender.

Roseibium: Roseibium is assigned to the neuter gender. However, the Greek noun bios (life) is in the masculine gender.

Sarcobium: Sarcobium is assigned to the neuter gender. However, the Greek noun bios (life) is in the masculine gender.

Sediminibacterium

Sinorhizobium: Sinorhizobium is assigned to the neuter gender. However, the Greek noun bios (life) is in the masculine gender.

Sphingobium: Sphingobium is assigned to the neuter gender. However, the Greek noun bios (life) is in the masculine gender.

Streptoverticillium: Streptoverticillium is assigned to the neuter gender. However, the Latin noun verticillus (whorl, whirl of a spindle) is in the masculine gender.

Sulfurihydrogenibium: Sulfurihydrogenibium is assigned to the neuter gender. However, the Greek noun bios (life) is in the masculine gender.

Thermoanaerobacterium

Thermoanaerobium: Thermoanaerobium is assigned to the neuter gender. However, the Greek noun bios (life) is in the masculine gender.

Thermobrachium

Thermochromatium

Thermocladium: Thermocladium is assigned to the neuter gender. However, the Greek noun klados (a branch, shoot of a tree) is in the masculine gender.

Thermocrispum

Thermodesulfobium: Thermodesulfobium is assigned to the neuter gender. However, the Greek noun bios (life) is in the masculine gender.

Thermodesulfobacterium

Tychonema (not validly published)

Azomonotrichon
The gender is not given by Thompson and Skerman 1981 and the specific epithet of the sole species does not allow the correct gender to be determined. However, according to rules of Latin and latinization, Azomonotrichon should be in the neuter gender.

Natronincola
The gender is not given by Zhilina et al. 1999 and the specific epithet of the sole species does not allow the correct gender to be determined. Natronincola may be in the masculine or in the feminine gender. According to Rule 65(1) when the original author failed to indicate the gender, a subsequent author has the right of choice.

Nonlabens
The gender is not given by Lau et al. 2005 and the specific epithet of the sole species does not allow the correct gender to be determined. Nonlabens may be in the masculine, in the feminine, or in the neuter gender. According to Rule 65(1) when the original author failed to indicate the gender, a subsequent author has the right of choice.