Pseudomonas

Pseudomonas is a genus of Gram-negative, rod-shaped, motile bacteria classified in the family Pseudomonadaceae. Members are typically aerobic or facultatively anaerobic, non-fermentative, and oxidase-positive. They display substantial metabolic versatility, enabling growth on a wide range of carbon sources and in diverse environments, including soil, water, plant surfaces, and man-made settings such as hospitals and industrial facilities.

Pseudomonas species are common environmental inhabitants and play roles in nutrient cycling. They are known for producing diverse secondary metabolites, including pigments such as the blue-green pyocyanin produced by Pseudomonas aeruginosa. Genomes of the genus are relatively large and generally have a high GC content, reflecting their genetic diversity and adaptability.

Pseudomonas aeruginosa is the best-known species and an important opportunistic human pathogen. It can cause severe infections in immunocompromised individuals, including pneumonia, bloodstream infections, urinary tract infections, wound infections, and infections in people with cystic fibrosis. The organism readily forms biofilms and often exhibits intrinsic and acquired antibiotic resistance, presenting challenges for treatment and infection control. While pathogenic strains receive the most attention, many Pseudomonas species are beneficial in natural ecosystems, plant growth promotion, or bioremediation.

In applied contexts, certain Pseudomonas strains are used for environmental cleanup, biodegradation of hydrocarbons, and production of biosurfactants. The genus remains a focus of microbiological research due to its metabolic breadth, ecological ubiquity, and clinical significance.