Gram-negative
Rod-shaped, 0.5-0.8 um x 1-3 um
Strictly aerobic; the only anaerobic activities may be denitrification and arginine degradation to ornithine
Motile by polar flagella; some strains also produce lateral flagella
Oxidative, chemoorganotrophic metabolism
Catalase-positive
Usually oxidase-positive
No organic growth factors are required
Diffusible and/or insoluble pigments may be produced
GC content of the DNA: 58-68 mol%
Morphological definition
Morphologically, members of the genus Pseudomonas (as well as most other pseudomonads) may be described as Gram-negative, non-spore forming, straight or slightly curved rods. They are typically motile by means of one or more polar flagella. These basic morphological characteristics, however, are common to many families of bacteria and so are of little value in the positive identification or diagnosis of a member of the genus Pseudomonas.
Availability
soils, fresh water and marine environments, and in many other natural habitats.