Once at the surface, bacteria cells anchor themselves with their sticky polymers. The association of bacteria with a surface and the development of a biofilm can be viewed as a survival mechanism. Bacteria benefit by capturing nutrients from the water and developing protection against disinfectants. Trace organics will concentrate on surfaces. Extracellular polymers will further concentrate trace nutrients from the bulk water.
Secondary colonizers use the waste products from their neighbors.
By pooling their biochemical resources, several species of bacteria, each armed with different enzymes, can break down food supplies that no single species could digest alone. In order to destroy the cell responsible for forming the biofilm, the disinfectant must first react with the surrounding polysaccharide network. The cells themselves are not actually more resistant, rather they have surrounded themselves with a protective shield. The disinfectant's oxidizing power can be used up before it reaches the cell. In fact, biofilm bacteria often produce more exopolymers after biocide treatment to further protect themselves.