Order Caulobacterales

Family Caulobacteraceae
Asticcacaulis - Brevundimonas - Caulobacter - Phenylobacterium

Order Kordiimonadales

Family "Kordiimonadaceae"
Kordiimonas

Order "Parvularculales"

Family "Parvularculaceae"
Parvularcula

Order Rhizobiales

Family "Aurantimonadaceae"
Aurantimonas - Fulvimarina - Martelella

Family Bartonellaceae
Bartonella - Grahamella - Rochalimaea

Family Beijerinckiaceae
Beijerinckia - Chelatococcus - Methylocapsa - Methylocella

Family Bradyrhizobiaceae
Afipia - Agromonas - Balneimonas - Blastobacter - Bosea - Bradyrhizobium - Nitrobacter - Oligotropha - Rhodoblastus - Rhodopseudomonas

Family Brucellaceae
Brucella - Crabtreella - Daeguia - Mycoplana - Ochrobactrum - Pseudochrobactrum

Family Cohaesibacteraceae
Cohaesibacter

Family Hyphomicrobiaceae
Ancalomicrobium - Angulomicrobium - Aquabacter - Blastochloris - Cucumibacter - Devosia - Dichotomicrobium - Filomicrobium - Gemmiger - Hyphomicrobium - Methylorhabdus - Pedomicrobium - Prosthecomicrobium - Rhodomicrobium - Rhodoplanes - Seliberia

Family Methylobacteriaceae
Meganema - Methylobacterium - Microvirga - Protomonas

Family Methylocystaceae
Albibacter - Methylocystis - Methylopila - Methylosinus - Pleomorphomonas - Terasakiella

Family Phyllobacteriaceae
Aminobacter - Aquamicrobium - Defluvibacter - Hoeflea - Mesorhizobium - Nitratireductor - Phyllobacterium - Pseudaminobacter

Family Rhizobiaceae
Agrobacterium - Allorhizobium - Carbophilus - Chelatobacter - Ensifer - Kaistia - Rhizobium - Sinorhizobium

Family Rhodobiaceae
Anderseniella - Parvibaculum - Rhodobium - Roseospirillum

Family Xanthobacteraceae
Ancylobacter - Azorhizobium - Labrys - Pseudolabrys - Pseudoxanthobacter - Starkeya - Xanthobacter