Rahnella
aquatilis - genomospecies

Ralstonia
eutropha - insidiosa - mannitolilytica - oxalaticus - picketti - pickettii - solanacearum - sp - sp. - syzygii

Ramlibacter
henchirensis - tataouinensis

Raoultella
ornithinolytica - planticola - terrigena

Rarobacter
faecitabidus - incanus

Rathayibacter
caricis - festucae - iranicus - rathayi - sp. - toxicus - tritici

Reinekea
marinisedimentorum

Renibacterium
salmoninarum

Rhabdochromatium
marinum

Rheinheimera
baltica - perlucida

Rhizobacter
dauci

Rhizobium
etli - galegae - hainanense - huautlense - larrymoorei - leguminosarum - lupini - mongolense - phaseoli - radiobacter - rhizogenes - rubi - sp. - sullae - trifolii - tropici - undicola - vitis - yanglingense

Rhizomonas
sp.

Rhodanobacter
spathiphylli

Rhodobacter
azotoformans - blasticus - capsulatus - sp. - sphaeroides - veldkampii

Rhodobium
marinum - orientis

Rhodoblastus
acidophilus

Rhodocista
centenaria

Rhodococcus
aetherivorans - baikonurensis - coprophilus - corynebacterioides - equi - erythropolis - fascians - globerulus - gordoniae - jostii - koreensis - kroppenstedtii - kunmingensis - luteus - maanshanensis - marinonascens - maris - opacus - percolatus - phenolicus - pyridinivorans - rhodnii - rhodochrous - ruber - rubropertinctus - sp. - triatomae - tukisamuensis - wratislaviensis - yunnanensis - zopfii

Rhodocyclus
purpureus - tenuis

Rhodoferax
fermentans - ferrireducens

Rhodomicrobium
vannielii

Rhodonellum
ikkaensis - psychrophilum

Rhodopila
globiformis

Rhodoplanes
elegans - roseus

Rhodopseudomonas
cryptolactis - julia - palustris - rhenobacensis - sp.

Rhodospirillum
photometricum - rubrum - sp.

Rhodothalassium
salexigens

Rhodothermus
marinus

Rhodovibrio
salinarum - sodomensis

Rhodovulum
adriaticum - euryhalinum - iodosum - robiginosum - strictum - sulfidophilum

Riemerella
anatipestifer - columbina

Rikenella
microfusus

Robiginitalea
biformata

Roseateles
depolymerans

Roseburia
faecis - hominis - intestinalis - inulinivorans

Roseibum
denhamense - hamelinense

Roseiflexus
castenholzii

Roseinatronobacter
thiooxidans

Roseivirga
ehrenbergii

Roseivivax
halodurans - halotolerans

Roseobacter
algicola - denitrificans - gallaeciensis - litoralis

Roseococcus
thiosulfatophilus

Roseomonas
cervicalis - fauriae - genomospecies - gilardii

Roseospira
marina - navarrensis

Roseospirillum
parvum

Roseovarius
crassostreae - mucosus - nubinhibens - tolerans

Rothia
aeria - amarae - dentocariosa - mucilaginosa - nasimurium

Rubrimonas
cliftonensis

Rubritepida
flocculans

Rubrivivax
gelatinosus

Rubrobacter
radiotolerans - xylanophilus

Ruegeria
algicola - atlantica - gelatinovorans

Rugamonas
rubra

Ruminobacter
amylophilus

Ruminococcus
albus - hansenii - hydrogenotrophicus - luti - productus - schinkii

Runella
limosa - slithyformis - zeae