Biofilm
![Staphylococcus aureus biofilm on an indwelling catheter](/Images/godic/202412/24/Staphylococcus_aureus_biofilm_014658.jpg")
![An iridescent biofilm on the surface of a fish tank.](/Images/godic/202412/24/Iridescent_biofilm_on_a_fishtank4658.JPG")
![Five stages of biofilm development: (1) Initial attachment, (2) Irreversible attachment, (3) Maturation I, (4) Maturation II, and (5) Dispersion. Each stage of development in the diagram is paired with a photomicrograph of a developing P. aeruginosa biofilm. All photomicrographs are shown to the same scale.](/Images/godic/202412/24/Biofilm4658.jpg")
![Mats of bacterial biofilm color the hot springs in Yellowstone National Park. The longest raised mat area is about half a meter long.](/Images/godic/202412/24/Bacteria_mats_near_Grand_Prismatic_Spring_in_Yellowstone-750px4658.JPG")
IUPAC definition
Aggregate of microorganisms in which cells that are frequently embedded within a self-produced matrix of extracellular polymeric substance (EPS) adhere to each other and/or to a surface.
Note 1: A biofilm is a system that can be adapted internally to environmental conditions by its inhabitants.