Pseudomonas is a genus of Gram-negative, Gammaproteobacteria, belonging to the family Pseudomonadaceae and containing 191 validly described species. The members of the genus demonstrate a great deal of metabolic diversity and consequently are able to colonize a wide range of niches. Their ease of culture in vitro and availability of an increasing number of Pseudomonas strain genome sequences has made the genus an excellent focus for scientific research; the best studied species include P. aeruginosa in its role as an opportunistic human pathogen, the plant pathogen P. syringae, the soil bacterium P. putida, and the plant growth-promoting P. fluorescens, P. lini, P. migulae, and P. graminis.
Pseudomonas fragi is a psychrophilic, Gram-negative bacterium that is responsible for dairy spoilage. Unlike many other members of the genus Pseudomonas, P. fragi does not produce siderophores. Optimal temperature for growth is 30 °C, however it can grow between 0 and 35 °C. Based on 16S rRNA analysis, P. fragi has been placed in the P. chlororaphis group.
Pseudomonas avellanae is a Gram-negative plant pathogenic bacterium. It is the causal agent of bacterial canker of hazelnut. Based on 16S rRNA analysis, P. avellanae has been placed in the P. syringae group. This species was once included as a pathovar of Pseudomonas syringae, but following DNA-DNA hybridization, it was instated as a separate species. Following ribotypical analysis Pseudomonas syringae pv. theae was incorporated into this species.
Pseudomonas ficuserectae is a nonfluorescent, Gram-negative, soil bacterium that causes bacterial leaf spot on a Japanese fig, from which it derives its name. Based on 16S rRNA analysis, P. ficuserectae has been placed in the P. syringae group.
Pseudomonas mendocina is a Gram-negative environmental bacterium that can cause opportunistic nosocomial (hospital-acquired) infections, such as infective endocarditis and spondylodiscitis, although cases are very rare. It has potential use in bioremediation as it is able to degrade toluene. Based on 16S rRNA analysis, P. mendocina has been placed in the P. aeruginosa group.
Pseudomonas flavescens is a Gram-negative bacterium that causes blight cankers on walnut trees. Based on 16S rRNA analysis, P. flavescens has been placed in the P. aeruginosa group.
Pseudomonas libanensis is a Gram-negative, rod-shaped, fluorescent, motile bacterium isolated from natural springs in Lebanon. Based on 16S rRNA analysis, P. libanensis has been placed in the P. fluorescens group.
Pseudomonas veronii is a Gram-negative, rod-shaped, fluorescent, motile bacterium isolated from natural springs in France. It may be used for bioremediation of contaminated soils, as it has been shown to degrade a variety of simple aromatic organic compounds. Based on 16S rRNA analysis, P. veronii has been placed in the P. fluorescens group.
Pseudomonas mosselii is a Gram-negative, rod-shaped, bacterium clinically isolated in France. Based on 16S rRNA analysis, P. mosselii has been placed in the P. putida group.
Pseudomonas palleroniana is a Gram-negative bacterium that infects rice. The type strain is CFBP 4389.
Pseudomonas amygdali is a Gram-negative plant pathogenic bacterium. It is named after its ability to cause disease on almond trees. Different analyses, including 16S rRNA analysis, DNA-DNA hybridization, and MLST clearly placed P. amygdali in the P. syringae group together with the species Pseudomonas ficuserectae and Pseudomonas meliae, and 27 pathovars of Pseudomonas syringae/Pseudomonas savastanoi, constituting a single, well-defined phylogenetic group which should be considered as a single species. This phylogenetic group has not been formally named because of the lack of reliable means to differentiate it phenotipically from closely related species, and it is currently known as either genomospecies 2 or phylogroup 3. When it is formally named, the correct name for this new species should be Pseudomonas amygdali, which takes precedence over all the other names of taxa from this group, including Pseudomonas savastanoi, which is and inadequate and confusing name whose use is not recommended.
Pseudomonas balearica is a Gram-negative, rod-shaped, nonfluorescent, motile, and denitrifying bacterium. It is an environmental bacterium that has been mostly isolated from polluted environments all over the world. Many of the isolates have demonstrated capabilities to degrade several compounds. Some of the strains are naphthalene degraders and one strain isolated in New Zealand has demonstrated the potential to oxidize inorganic sulfur compounds to tetrathionate. Based on 16S rRNA analysis, P. balearica has been placed in the P. stutzeri group.
Pseudomonas plecoglossicida is a non-fluorescent, Gram-negative, rod-shaped, motile bacterium that causes hemorrhagic ascites in the ayu fish, from which it derives its name. Based on 16S rRNA analysis, P. plecoglossicida has been placed in the P. putida group.
Pseudomonas cedrina is a Gram-negative, rod-shaped bacterium isolated from spring waters in Lebanon. Based on 16S rRNA analysis, P. cedrina has been placed in the P. fluorescens group.
Pseudomonas orientalis is a Gram-negative, rod-shaped bacterium isolated from spring waters in Lebanon. Based on 16S rRNA analysis, P. orientalis has been placed in the P. fluorescens group.
Pseudomonas mandelii is a fluorescent, Gram-negative, rod-shaped bacterium isolated from natural spring waters in France. Based on 16S rRNA analysis, P. mandelii has been placed in the P. fluorescens group.
Pseudomonas migulae is a fluorescent, Gram-negative, rod-shaped bacterium isolated from natural mineral waters in France. This bacterium has also been isolated from endophytic tissues of lodgepole pine trees growing on gravel mining sites with potential to perform biological nitrogen fixation and plant growth promotion. Based on 16S rRNA analysis, P. migulae has been placed in the P. fluorescens group.
Pseudomonas gessardii is a fluorescent, Gram-negative, rod-shaped bacterium isolated from natural mineral waters in France. Based on 16S rRNA analysis, P. gessardii has been placed in the P. fluorescens group.
Pseudomonas rhodesiae is a Gram-negative, rod-shaped bacterium isolated from natural mineral waters. Based on 16S rRNA analysis, P. rhodesiae has been placed in the P. fluorescens group.
Pseudomonas costantinii is a Gram-negative bacterium that causes brown blotch disease in cultivated mushrooms. It demonstrates hemolytic activity. The type strain is CFBP 5705.
