Abiotrophia
defectiva

Acaricomes
phytoseiuli

Acetitomaculum
ruminis

Acetivibrio
cellulolyticus - ethanolgignens - multivorans

Acetobacter
aceti - cerevisiae - cibinongensis - estunensis - indonesiensis - lovaniensis - malorum - orientalis - orleanensis - pasteurianus - pomorum - syzygii - tropicalis

Acetobacterium
bakii - carbinolicum - dehalogenans - fimetarium - malicum - paludosum - sp. - tundrae - wieringae - woodii

Acetohalobium
arabaticum

Acetomicrobium
faecale - flavidum

Acetonema
longum

Achromobacter
denitrificans - immobilis - piechaudii - ruhlandii - xylosoxidans

Acidaminobacter
hydrogenoformans

Acidaminococcus
fermentans

Acidianus
ambivalens - brierleyi - infernus

Acidicaldus
organivorans

Acidilobus
aceticus

Acidimicrobium
ferrooxidans

Acidiphilium
acidophilum - cryptum - multivorum

Acidithiobacillus
albertensis - caldus - ferrooxidans - thiooxidans

Acidobacterium
capsulatum

Acidocella
aminolytica

Acidomonas
methanolica

Acidovorax
anthurii - avenae - defluvii - delafieldii - facilis - konjaci - sp. - temperans - valerianellae

Acinetobacter
baumannii - baylyi - bouvetii - calcoaceticus - genospecies - gerneri - grimontii - haemolyticus - johnsonii - junii - lwoffii - parvus - radioresistens - schindleri - sp. - tandoii - tjernbergiae - towneri - ursingii

Acrocarpospora
corrugata - macrocephala - pleiomorpha

Actinacidiphilus
wushanense

Actinoacidiphilus
directus - flexuosus - helicoides

Actinoalloteichus
cyanogriseus - spitiensis

Actinobacillus
delphinicola - pleuropneumoniae - rossii - ureae

Actinobaculum
schaalii - suis - urinale

Actinocatenispora
thailandica

Actinocorallia
aurantiaca - cavernae - glomerata - herbida - libanotica - longicatena

Actinokineospora
auranticolor - diospyrosa - enzanensis - globicatena - inagensis - riparia - terrae

Actinomadura
alba - atramentaria - catellatispora - chibensis - citrea - coerulea - cremea - echinospora - fibrosa - formosensis - fulvescens - glauciflava - hallensis - hibisca - kijaniata - latina - livida - luteofluorescens - macra - madurae - mexicana - meyerae - namibiensis - napierensis - nitritigenes - oligospora - pelletieri - rubrobrunea - rudentiformis - rugatobispora - sp. - spadix - umbrina - verrucosospora - vinacea - viridilutea - viridis

Actinomyces
bovis - bowdenii - canis - cardiffensis - catuli - coleocanis - denticolens - europaeus - funkei - georgiae - gerencseriae - graevenitzii - hongkongensis - hordeovulneris - hyovaginalis - israelii - marimammalium - meyeri - naeslundii - neuii - odontolyticus - oricola - radicidentis - radingae - suimastitidis - turicensis - urogenitalis - vaccimaxillae - viscosus

Actinoplanes
auranticolor - brasiliensis - campanulatus - capillaceus - consettensis - couchii - cyaneus - deccanensis - derwentensis - digitatis - durhamensis - ferrugineus - garbadinensis - globisporus - gratiae - humidus - italicus - liguriensis - lobatus - missouriensis - palleronii - philippinensis - rectilineatus - regularis - sp. - teichomyceticus - utahensis

Actinopolyspora
halophila - iraqiensis - mortivallis - salina - sp. - xinjiangensis

Actinospica
acidiphila - robiniae

Actinostreptospora
chiangmaiensis

Actinosynnema
mirum - pretiosum

Actinotalea
fermentans

Actinotelluria
brasiliensis

Adhaeribacter
aquaticus

Aequorivita
antarctica - crocea - lipolytica - sublithincola

Aerococcus
christensenii - sanguinicola - urinae - urinaeequi - urinaehominis - viridans

Aeromicrobium
alkaliterrae - erythreum - fastidiosum - marinum

Aeromonas
allosaccharophila - bestiarum - caviae - encheleia - enteropelogenes - eucrenophila - hydrophila - ichthiosmia - jandaei - media - molluscorum - salmonicida - schubertii - sharmana - simiae - veronii

Aeropyrum
camini - pernix

Aestuariibacter
halophilus - salexigens

Afipia
birgiae - broomeae - clevelandensis - felis - massiliensis

Aggregatibacter
actinomycetemcomitans

Agitococcus
lubricus

Agreia
bicolorata - pratensis

Agrobacterium
agile - luteum - sp.

Agrococcus
baldri - casei - citreus - jenensis - lahaulensis

Agromonas
oligotrophica

Agromyces
albus - aurantiacus - bracchium - cerinus - fucosus - hippuratus - humatus - italicus - lapidis - luteolus - mediolanus - neolithicus - ramosus - rhizospherae - salentinus - subbeticus - ulmi

Ahrensia
kielensis

Albidovulum
inexpectatum

Alcaligenes
faecalis - sp.

Alcanivorax
borkumensis - jadensis - venustensis

Algibacter
lectus

Algicola
sagamiensis

Algoriphagus
antarcticus - halophilus - winogradskyi

Alicycliphilus
denitrificans

Alicyclobacillus
acidiphilus - acidocaldarius - acidoterrestris - cycloheptanicus - disulfidooxydans - herbarius - hesperidum - pomorum - sendaiensis - sp. - tolerans - vulcanalis

Alishewanella
fetalis

Alistipes
finegoldii - putredinis

Alkalibacillus
filiformis - haloalkaliphilus - salilacus

Alkalibacter
saccharofermentans

Alkalibacterium
olivapovliticus

Alkalilimnicola
halodurans

Alkalispirillum
mobile

Alkanindiges
hongkongensis - illinoisensis

Allisonella
histaminiformans

Allobaculum
stercoricanis

Allochromatium
minutissimum - vinosum - warmingii

Allofustis
seminis

Alteromonas
macleodii - sp. - stellipolaris

Alysiella
crassa - filiformis

Aminobacter
aganoensis - aminovorans - ciceronei - lissarensis - niigataensis

Aminobacterium
colombiense - mobile

Aminomonas
paucivorans

Ammonifex
degensii

Ammoniphilus
oxalaticus - oxalivorans

Amphibacillus
fermentum - tropicus - xylanus

Amycolatopsis
alba - albidoflavus - australiensis - azurea - balhimycina - benzoatilytica - canyonensis - coloradensis - decaplanina - eurytherma - fastidiosa - halotolerans - japonica - jejuensis - kentuckyensis - keratiniphila - lexingtonensis - lurida - mediterranei - methanolica - minnesotensis - nigrescens - orientalis - palatopharyngis - plumensis - pretoriensis - rifamycinica - rubida - saalfeldensis - sacchari - sp. - sulphurea - thermoflava - tolypomycina - vancoresmycina

Anaeroarcus
burkinensis

Anaerobacter
polyendosporus

Anaerobaculum
mobile - thermoterrenum

Anaerobiospirillum
succiniciproducens - thomasii

Anaerobranca
californiensis - gottschalkii - horikoshii

Anaerocellum
thermophilum

Anaerococcus
hydrogenalis - lactolyticus - octavius - prevotii - tetradius - vaginalis

Anaerofilum
agile - pentosovorans

Anaerofustis
stercorihominis

Anaerolinea
thermophila

Anaeromusa
acidaminophila

Anaerophaga
thermohalophila

Anaeroplasma
sp.

Anaerosinus
glycerini

Anaerostipes
caccae

Anaerotruncus
colihominis

Anaerovibrio
lipolyticus

Anaerovirgula
multivorans

Anaerovorax
odorimutans

Ancalomicrobium
adetum

Ancylobacter
aquaticus - polymorphus - rudongensis - sp. - vacuolatus

Aneurinibacillus
aneurinilyticus - migulanus - thermoaerophilus

Angiococcus
disciformis - sp.

Angulomicrobium
amanitiforme - tetraedrale

Anoxybacillus
amylolyticus - contaminans - flavithermus - kamchatkensis - pushchinoensis - voinovskiensis

Antarctobacter
heliothermus

Aquabacter
spiritensis

Aquabacterium
citratiphilum - commune - parvum

Aquamicrobium
defluvii

Aquaspirillum
arcticum - bipunctata - denitrificans - elegans - itersonii - peregrinum - polymorphum - putridiconchylium - serpens - sp.

Aquicella
lusitana - siphonis

Aquifex
pyrophilus

Aquiflexum
balticum

Aquimarina
brevivitae - latercula

Aquimonas
voraii

Arcanobacterium
bernardiae - bialowiezense - bonasi - haemolyticum - hippocoleae - phocae - pluranimalium - pyogenes

Archaeoglobus
fulgidus - profundus - veneficus

Archangium
gephyra

Arcicella
aquatica

Arcobacter
butzleri - cibarius - cryaerophilus - halophilus - nitrofigilis - skirrowii

Arenibacter
palladensis

Arhodomonas
aquaeolei

Arsenicicoccus
bolidensis

Arsenophonus
nasoniae

Arthrobacter
agilis - albus - ardleyensis - arilaitensis - atrocyaneus - aurescens - bergerei - castelli - chlorophenolicus - citreus - creatinolyticus - crystallopoietes - cumminsii - dextranlyticum - gandavensis - gangotriensis - globiformis - histidinolovorans - ilicis - kerguelensis - koreensis - luteolus - methylotrophus - monumenti - mysorens - nasiphocae - nicotianae - nicotinovorans - nitroguajacolicus - oxydans - parietis - pascens - pigmenti - polychromogenes - protophormiae - psychrolactophilus - psychrophenolicus - ramosus - roseus - russicus - scleromae - sialophilus - sp. - stackebrandtii - sulfonivorans - sulfureus - tecti - tumbae - uratoxydans - ureafaciens - viscosus - woluwensis

Asanoa
ferruginea - iriomotensis - ishikariensis

Asticcacaulis
biprosthecium - excentricus

Astrosporangium
hypotensionis

Atopobium
fossor - minutum - parvulum - rimae - vaginae

Atopococcus
tabaci

Atopostipes
suicloacalis

Aurantimonas
coralicida

Avibacterium
avium - gallinarum - volantium

Azoarcus
anaerobius - buckelii - evansii - sp. - toluvorans

Azohydromonas
australica - lata

Azomonas
agilis - insignis - macrocytogenes

Azorhizobium
caulinodans

Azorhizophilus
paspali

Azospira
oryzae

Azospirillum
amazonense - brasilense - doebereinerae - halopraeferens - irakense - lipoferum - sp.

Azotobacter
armeniacus - beijerinckii - chroococcum - nigricans - salinestris - sp. - vinelandii