| Morphology | Xanthobacter |
| CELLULAR |
| Staining | The Gram-reaction is positive or variable; however, the ultrastructure of the cell wall seems to be of the negative Gram- type, the peptidoglycan id directly cross-linked by meso-diaminopimelic acid, and lipopolysaccharides are present. |
| Morphology | Rod-shaped cells 0.4-1.0 um in diameter and 0.8-6.0 um in length. Pleomorphic cells are produced on succinate-containing media; coccoid cells as well as cells up to 10 um long are produced on media containing an alcohol as the sole carbon source. |
| Motility | Nonmotile or motile by peritrichous flagella |
| Specialized structures | Refractile (polyphosphate) and lipid (poly-B-hydroxybutyric acid) bodies are evenly distributed in the cells. Resting stages are unknown.. |
| Division |
| COLONIAL |
| Solid surface | Colonies are opaque and slimy (although slime-free strains exist) and are yellow due to a water-insoluble carotenoid pigment (zeaxanthin dirhamnoside |
| Liquid |
| Growth Parameters | Xanthobacter |
| PHYSIOLOGICAL |
| Tropism | All strains can grow as chemolithoautotrophs in mineral media under an atmosphere of H2, O2 and CO2 (7:1:1, v/v) as well as chemoorganotrophically on methanol, ethanol, n- propanol, n-butanol, and various organic acids as sole carbon sources. |
| Oxygen | Obligately aerobic, having a strictly respiratory type of metabolism with oxygen as the terminal electron acceptor |
| pH | Optimum pH, 5.8-9.0 |
| Temperature | Optimum temperature 25-30 |
| Requirements | Carbohydrate utilization is limited, and neither volatile/nonvolatile fatty acids nor gas are produced from some carbohydrates. Some strains require vitamins. |
| Products | Atmospheric nitrogen is fixed in nitrogen-deficient media, but by most strains only under a decreased oxygen pressure; the efficiency is more than 10 mg of nitrogen fixed/g of sucrose consumed, and is usually 20 mg/g. |
| Enzymes | Catalase-positive |
| Unique features |
| ENVIRONMENTAL |
| Habitat | The organisms occur free-living in wet soil containing decaying organic material, and also in water. The induction of root nodules on plants has not been observed |
| Lifestyle | |
| Pathogenicity |
| Distribution |
| Genome | Xanthobacter |
| G+C Mol % | 66-68 |
| Reference | Xanthobacter |
| First citation | Wiegel, J., D.Wilke, J. Baumgarten, R. Opitz and H.G. Schlegel (1978) Transfer of the nitrogen-fixing hydrogen bacterium Coyrnebacterium autotrophicum Baumgarten et al to Xanthobacter gen. Nov. IJSB 28: 573-581 |
| The Prokaryotes | P |
| Bergey's Systematatic | p 325 J.K.W. Wiegel and H. G. Schlegel |
| Bergey's Determinative | p 99 |
| References |