What is Pseudomonas Fluorescens?

Mary McMahon
Mary McMahon

Pseudomonas fluorescens is a gram negative bacterium in a genus of bacteria commonly found in decaying organic material like rotting leaves and soil. These bacteria are common sources of food contamination and they have a number of potential applications that make them topics of interest in the laboratory environment. Samples of Pseudomonas fluorescens for study are available from some companies that supply stabilized bacteria for research in samples designed to be free of contaminants.

Mupirocin may be used to treat ear infections.
Mupirocin may be used to treat ear infections.

These bacteria are aerobic, requiring oxygen to survive, and they have flagella, small hair-like structures used for motility. As their name implies, they contain fluorescent pigments. Pseudomonas fluorescens is of interest and concern in hospital settings because the bacteria are known to resist many antibiotics and antiseptic products. In patients with healthy immune systems, these bacteria can often exist peacefully on or in the body, but in people with compromised immune systems, they can become dangerous. Pseudomonas fluorescens bacteria have been linked with infections in cancer patients, most notably in the case of biofilms that colonize intravenous lines. In rare cases, these bacteria have infected the bloodstream, causing bacteremia, a condition that can lead to complications like shock.

Samples of Pseudomonas fluorescens are available from some companies that supply stabilized, contaminant-free bacteria for research.
Samples of Pseudomonas fluorescens are available from some companies that supply stabilized, contaminant-free bacteria for research.

These bacteria also make their own antibiotic, a compound known as mupirocin. This antibiotic has some potential applications in the treatment of skin and ear infections. In addition, Pseudomonas fluorescens colonization can be beneficial for plants. Having these bacteria in a root system may help plants resist fungal infections and can help plants absorb nutrients more effectively. These two positive uses of the bacterium have been explored in a number of laboratories.

Pseudomonas fluorescens has another trick up its sleeve. These bacteria can break down a variety of contaminants including plastics and may be useful for bioremediation programs. In such programs, bacteria are introduced to contaminated areas to clean them up. These bacteria are beneficial because presumably once finished with the contaminants, they could linger to help newly established plants develop a foothold and grow in a healthy environment.

In food, Pseudomonas fluorescens is a common contaminant, especially since it actively enjoys lower temperatures like those found in fridges. Dairy products are especially vulnerable to Pseudomonas fluorescens contamination. The use of regular testing to check for contaminants, as well as controls in facilities where food is produced, is critical to identify contaminants and halt production until they can be dealt with while contaminated products are pulled before they have a chance to enter the supply chain.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

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Discussion Comments


Esp. for starry night: pseudomonas fluorescens: diagnosed with this. I fight chronic, disabling infection.


Pseudomonas fluorescens may turn our landfills into parks, but it's putting me and other Cystic Fibrosis patients in the hospital!


@starrynight - I think that's a lovely view of the future. I too hope that someday we can take steps to improve our environment.

I also find it really interesting that this bacteria produces it's own antibiotic. It almost seems counterintuitive, because an antibiotic works against bacteria and pseudomonas fluorescens is, of course, a bacterium.


What an interesting bacterium! It's fluorescent and breaks down plastic! I think more studies definitely need to be done on this wonder bug because plastic is a huge environmental problem.

I may be reaching here, but maybe with the help of pseudomonas fluorescens we could eventually turn some of our landfills into parks.

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