Biofilm

A biofilm is a structured community of microbes in a matrix of polysaccharides, secreted proteins, proteins from lysed cells, DNA and RNA mainly from lysed cells, and ions. Biofilms tend to form on: 1) smooth and 2) wet surfaces because these surfaces tend to accumulate nutrients easily. Examples of such surfaces are teeth, intestines, toilet bowls, and flower vases.

Biofilms are formed when a quorum is achieved. Quorums are achieved by a process called '''quorum sensing. '''Quorum sensing occurs when autoinducers, signal molecules that are constantly secreted by microbial cells, reach a concentration at which biofilm genes are activated (often by repressor deactivation).