Pseudomonas putida is a commonly studied bacterium strain in laboratories. As per its characteristic features, it is grouped under rod-shaped, gram negative bacteria. Requiring oxygen for growth and survival, this aerobic bacterium inhabits soil, water, and other habitats, where there is availability of abundant oxygen and organic nutrients. It is motile and uses polar flagella for movement purpose. In scientific history, the first living organism to obtain patent was P. putida.
The optimal temperature range for growth of these bacteria is 25-30° C. The metabolism diversity of P. putida is worth mentioning. It has the ability to metabolize non-biodegradable oils, Styrofoam, and plastic from the soil, converting them into simpler forms. Another application of it is in the synthesis of organic substances, like benzene. When it comes to pathogenicity, it is identified as a safe, but occasionally opportunistic pathogen.
Represented by the scientific name Pseudomonas putida, pseudomonas is the genus name and putida is the species name. In the taxonomical classification, P. putida is grouped under the class Gamma proteobacteria of the phylum Proteobacteria. The family for this saprophytic soil bacterium is Pseudomonadaceae and order is Pseudomonales.
It is a rod-shaped bacterium that possesses flagella. In the natural habitats and in vitro culture medium, P. putida forms biofilms with the help of extracellular polymeric substances (EPS). This EPS is a matrix secreted by the bacterial cells themselves. When present in non-hydrated condition, like leaf surface and soil, these aerobic bacteria are present in small colonies or small patches.
P. putida is isolated from body parts of some patients, who are diagnosed with chronic sinusitis. There is a medical report that highlights its infection in newborn babies. The manifested skin symptoms are similar to that of staphylococcal scalded skin syndrome. In other cases, neonatal septicemia with it is observed in preterm babies. These infections indicate the need for proper aseptic maintenance in health care centers. Its treatment is done with a specific dose of antibiotics.
Use in Bioremediation
The bacterial species belonging to genus Pseudomonas are remarkable for their bioremediation properties, and P. putida is effective for treating polluted soil that contains nicotine, naphthalene, toluene, and oil, as some of the contaminants. These beneficial bacteria also degrade plastic and polystyrene into biodegradable products. Thus, this bacterium is useful for restoring normal conditions in an otherwise polluted soil.
Relationship with Plants
P. putida form colonies and thrive in the plant roots. No doubt, they feed on the nutrients present in the rhizosphere, but, these bacteria live in harmonious relationship with the host plants by protecting them from pathogens and increasing the nutrient absorption. Current studies are ongoing for its use in making biopesticides for crops and valuable plants.
Use in Agriculture
A beneficial property of all pseudomonas bacteria is that, it helps the plants to absorb nutrients from the soil medium. The same is applicable to P. putida, which also aids in counteracting pathogenic fungi, like fusarium and pythium. The former causes wilt disease in plants; while pythium inhabits the rhizosphere, and causes damping of disease in newly sprouted seedlings and young plants.
As of date, scientists have completed the sequencing of several strains of P. putida. In the result, it is cited that this simple bacterium is made up of about 6.2 million base pairs. Huge interest has been shown in sequencing the genome of other strains for use in pollution control measures. Also, practical use of this bacterium has been put forth for degrading oils and other organic pollutants. The plus point of employing this bacterium strain over other species of pseudomonas is its non-pathogenic nature.