Table 1.
Members of the Rizobiales order analyzed in this study
| Genera | Number of species | Number of strains | Habitat or metabolism | Range of chromosomes number | Range of plasmids number |
|---|---|---|---|---|---|
| Agrobacterium | 4 | 4 | Plant Pathogen | 1–2 | 2 |
| Aureimonas (formely Aurantimonas) | 1 | 1 | Potential human pathogen and different environmental sources | 1 | 8 |
| Bartonella | 2 | 2 | Mammalian pathogens | 1 | 1–2 |
| Beijerinckia | 1 | 1 | Free‐living in soil | 1 | 2 |
| Bosea | 1 | 1 | Thiosulfate‐oxidizing/plant associated | 1 | 1 |
| Bradyrhizobium | 1 | 1 | Facultative symbiotic diazotrophs | 1 | 1 |
| Brucella | 5 | 5 | Mammalian pathogens | 2 | 0 |
| Chelativorans | 2 | 2 | EDTA‐degrading | 1 | 3 |
| Ensifer | 1 | 1 | Facultative symbiotic diazotrophs | 2 | 2 |
| Hoeflea | 1 | 1 | Marine Iron‐oxidizing | 1 | 2 |
| Martelella | 1 | 1 | Halophyte | 1 | 2 |
| Mesorhizobium | 2 | 2 | Facultative symbiotic diazotrophs | 1 | 1–2 |
| Methylobacterium | 5 | 7 | Methylotrophic plant‐associated | 1 | 1–8 |
| Neorhizobium | 1 | 1 | Facultative symbiotic diazotrophs | 1 | 2 |
| Nitrobacter | 1 | 1 | Nitrite‐oxidizing free‐living in soil | 1 | 3 |
| Ochrobactrum | 1 | 1 | Opportunistic human pathogen | 2 | 4 |
| Oligotropha | 1 | 2 | Wastewater CO‐utilizing | 1 | 1–2 |
| Pelagibacterium | 1 | 1 | Seawater halotolerant | 1 | 1 |
| Rhizobium | 3 | 7 | Facultative symbiotic diazotrophs | 1 | 1–6 |
| Rhodopseudomonas | 1 | 1 | Photosynthetic, nitrogen and carbón fixer | 1 | 1 |
| Shinella | 1 | 1 | Degradation of toxic aromatic compounds | 1 | 12 |
| Sinorhizobium | 3 | 8 | Facultative symbiotic diazotrophs | 1 | 1–4 |
| Xanthobacter | 1 | 1 | Chemolitho‐autotrophic free‐living diazotroph | 1 | 1 |
| 23 | 40 | 53 |