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.