Pseudomonas fluorescens is a common Gram-negative, rod-shaped bacterium that secretes a soluble fluorescent pigment called fluorescein. P. fluorescens has multiple flagella. It has an extremely versatile metabolism, and can be found in the soil and in water, where it can cause fin rot in fish. It is an obligate aerobe but certain strains are capable of using nitrate instead of oxygen as a final electron acceptor during cellular respiration.

Heat stable lipases and proteases are produced by Pseudomonas fluorescens and other similar pseudomonads (Frank 1997). These enzymes cause milk to spoil, by causing bitterness, casein breakdown, and ropiness due to production of slime and coagulation of proteins (Jay 2000, Frank 1997, Ray 1996).

Biocontrol properties

some P.fluorescens strains (CHA0 or Pf5 for example) present biocontrol properties, protecting the roots of some plant species against parasitic fungis (take-all disease) and phytophagous nematodes.

Pseudomonadales