Pseudomonas fluorescens
Morgan Boresi

Pseudomonas fluorescens is an obligate aerobe, gram negative bacillus.  These bacteria are able to inhabit many environments, including: plants, soil, and water surfaces.  Its name comes from its production of the soluble fluorescent pigment pyoverdin.  These microbes have multiple polar flagella for motion and use siderphores to aid in their collection of iron.  These bacteria are easy to culture, as they grow on minimal media and at 25-30 degrees Celsius.  They also grow fairly quickly.  All around the production of these microbes is very economical.

P. fluorescens is well known for some of its more heroic properties.  Firstly it is invaluable to agricultural technologies.  These bacteria will reside around the roots of plants/crops.  They get certain nutrients and environmental protection from the plants they reside near and in return, aid the plant in several ways.  They destroy certain toxins and pollutants including styrene, polycyclic aromatic hydrocarbons, and TNT.  They also protect the plants from infection by pathogens by producing secondary metabolites like antibiotics and hydrogen cyanide which kill other bacteria and fungi.  They also keep other pathogens at bay by competitive exclusion due to their rapid colonization.  It has been theorized that P. fluorescens could be a good alternative to synthetic pesticides because of its toxicity to larvae and the pupae of vector mosquitoes, two main concerns in the agricultural business. Furthermore, these microbes produce substances that aid in the plants ability to obtain key nutrients.

Not only is P. fluorescens a hero in the agricultural community, they are also very helpful to the human species. The antibiotics that help to protect plant roots also are used to treat infections in humans.  P. Fluorescens’ produce the antibiotic Mupirocin, which is used in skin, ear, and eye creams, ointment, and sprays.  Derivatives of Mupirocin are used in the treatment of dangerous Methicillin-resistant Staphylococcus aureus, which is difficult to treat with less specialized antibiotics. They also are used in certain food products, mainly, the production of yogurt.  They cause the degradation of certain proteins leading to the appearance of the trademark sour taste.

All around these bacteria are considered a very mild hazard.  They have only been known to infect immuno-compromised patients, such as cancer patients and those with immunodeficient diseases like lupus.  There only danger is to the small percentage of humans in the categories above and in food spoilage.  The properties of P. fluorescens that make it useful in the production of yoghurt also make it a spoiling agent in milk.  Although they grow best in 25-30 degree Celsius environments, they are known to be sustained at temperatures as low as 4 degrees Celsius such as those in a refrigerator.  P. fluorescens are commonly found in biofilms on spoiled dairy products.

By far P. fluorescens is more helpful than harmful and can be considered a quite heroic microorganism.  Thanks Pseudomonas Fluorescens!

Sources

http://en.wikipedia.org/wiki/Pseudomonas_fluorescens

http://microbewiki.kenyon.edu/index.php/Pseudomonas_fluorescens

http://genome.jgi-psf.org/finished_microbes/psefl/psefl.home.html

http://www.ebi.ac.uk/2can/genomes/bacteria/Pseudomonas_fluorescens.html

http://www.thelabrat.com/restriction/sources/Pseudomonasfluorescens.shtml

www.scienceclarified.com/.../uesc_02_img0068.jpg

www.wsu.edu/~mavrodi/q8r1.htm

*Disclaimer - This report was written by a student participaring in a microbiology course at the Missouri University of Science and Technology. The accuracy of the contents of this report is not guaranteed and it is recommended that you seek additional sources of information to verify the contents.

 

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