Pseudomonas stutzeri is a Gram-negative soil bacterium that is motile, has a single polar flagellum, and is classified as bacillus, or rod-shaped.

[1][2] While this bacterium was first isolated from human spinal fluid,[3] it has since been found in many different environments due to its various characteristics and metabolic capabilities.

[6] P. mendocina, P. alcaligenes, P. pseudoalcaligenes, and P. balearica are classified within the same branch of pseudomonads as P. stutzeri based on 16S rRNA sequences and other phylogenetic markers.

[10] The organism has been isolated from a wide variety of places such as human spinal fluid, straw, manure, soil, and canal water.

[16] Similar to other bacteria within the Pseudomonas genus, P. stutzeri strains are heterotrophic organisms that are capable of reducing metals and degrading compounds such as hydrocarbons.

[18] P. stutzeri strains are capable of growing on several various types of media because they can use different electron donors and acceptors to fuel their metabolisms.

[17] The bacterium frequently utilizes organic compounds as its electron donors, some of which include: glucose, lactate, acetate, succinate, pyruvate, sucrose and fumarate.

[10] When in aerobic environments, P. stutzeri can even grow on more complex media such as lysogeny and Reasoner's 2A (R2A) broths,[17] with the latter of the two being significantly useful in selecting for specific microbes due to its lack of abundant nutrients.

[20] Strains tested by Stainer and coworkers were able to grow and utilize the following substrates: gluconate, D-glucose, D-maltose, starch, glycerol, acetate, butyrate, isobutyrate, isovalerate, propionate, fumarate, glutarate, glycolate, glyoxylate, DL-3-hydroxybutyrate, itaconate, DL-lactate, DL-malate, malonate, oxaloacetate, 2-oxoglutarate, pyruvate, succinate, D-alanine, D-asparagine, L-glutamate, L-glutamine, L-isoleucine, and L-proline and hydrolysis of L-alanine-para-nitroanilide.

[6] D-maltose, starch, and ethylene glycol are carbon sources that are not commonly utilized by other pseudomonads as shown by Stainer et al.

[21] The oxidation of thiosulfate to tetrathionate cannot support autotrophic growth as it only yields one electron, therefore strains that perform this are obligate heterotrophs.

[6] In 1998, Metcalf and Wolfe enriched for and isolated a P. stutzeri strain WM88 that could oxidize reduced phosphorus compounds, such as phosphite and hypophosphite, to phosphate.

[22] To enrich for a hypophosphite-utilizing organism, a 0.4% glucose-MOPS medium containing 0.5 mM hypophosphite was used as the sole phosphorus source with inoculum from a variety of soil and water environments.

[22] When grown anaerobically, the researchers showed P. stutzeri is unable to perform hypophosphite oxidation with nitrate as its electron acceptor.

[6] Carbon tetrachloride can be a pollutant in soils and groundwater,[6] and according to the Center for Disease Control and Prevention (CDC) it is able to cause kidney damage and even death in individuals exposed to it for long periods of time.

[6] Strain P16 of P. stutzeri is a polycyclic aromatic hydrocarbon (PAH) degrading bacterium[6] that was isolated from creosote-contaminated soil via a phenanthrene enrichment culture.

[6] The habitats and ecology of P. stutzeri are diverse not only because of its ability to grow organotrophically or anaerobically using oxidative metabolism, but also because of its chemolithotrophic properties, its resistance to metals, the wide sources of nitrogen it can use, and the range of temperatures that support its growth.

[6] This strain meets the requirements of being able to tolerate NaCl and it is found in water columns in the Pacific Ocean and sediments in the Mediterranean.

[6] These marine strains have many ecological roles including naphthalene degradation, sulfur oxidation, and most importantly denitrification and diazotrophy (nitrogen fixation).

[11] Within those infected, P. stutzeri strains have been isolated from the blood, feces, cerebral spinal fluid, ears, eyes, and organ systems (such as respiratory and urinary).

[6] Despite its lack of major virulence, however, this bacterium still poses a threat to human health because it contains a variety of antibiotic resistance mechanisms.

[31] Some of the more-studied resistance mechanisms include: utilization of beta-lactamases, which are able to cleave penicillins, cephalosporins, and other antibiotic classes, and ability to vary lipopolysaccharide and outer membrane protein components.

[31] Some strains of P. stutzeri are capable of associating with pollutants and toxic metals, such as biocides and oil derivatives, in such a way that allows the bacterium to promote the degradation of these substances.