Biofilm

A biofilm is a microbial consortium embedded in a self-produced polysaccharide matrix attached to a surface.

Biofilm formation occurs in four stages — attachment, colonization, development, and dispersal.

During attachment, planktonic cells adhere to a surface.

In colonization, cells produce extracellular polysaccharides, forming a sticky matrix that binds them together into a biofilm.

During maturation, the biofilm develops into multilayered structures, which protects microorganisms from environmental stresses.

Occasionally, some cells may detach and disperse to colonize new surfaces.

While dispersal allows for biofilm expansion, the remaining structure continues to resist external challenges, including antibiotics, by limiting drug penetration and reducing metabolic activity within the matrix.

This allows biofilms to evade immune responses and persist in diseases like cystic fibrosis, where they obstruct airways.

Other harmful effects include dental plaque, leading to tooth decay, and biofilms on medical devices like catheters, which cause infections.

Biofilms can also provide ecological benefits by breaking down organic matter for nutrient cycling and supporting wastewater treatment through pollutant degradation.