From: biologydictionary.net
A biofilm is a thick layer of prokaryotic organisms that come together to form a colony.
This colony attaches to a surface using a slime layer, which serves to protect the microorganisms within it. Biofilms are found in various environments. They appear to be cooperative, sending out signals to each other and protective organisms.
Structure:
A microbial biofilm consists of many prokaryotic organisms that aggregate to form a colony. The colony adheres to a surface and is coated with a polysaccharide layer (the slime layer). Within this slime layer, there are porous channels that allow nutrients to reach the cells at the center of the colony and facilitate waste removal. Biofilms can be composed of both gram-positive and gram-negative bacteria
Formation and Maintenance:
Biofilms form and persist through cell-to-cell communication. It all begins when a few cells attach to a surface. These initial cells produce proteins that act as signals to nearby cells. Neighboring cells detect these signals and join the colony, growing the biofilm. The proteins also signal the development of the polysaccharide slime layer. Essentially, biofilms are a cooperative effort among cells to thrive and survive.
Biofilms serve several purposes:
Metabolic cooperation: Cells aggregate for mutual benefit, enhancing defense, nutrient availability, and genetic material transfer. The slime layer acts as an adhesive, preventing physical removal and immune system penetration. That slime layer acts as an invisibility cloak to hide from the immune system. It also acts as a glue if it is trying to stop an irritating action.
Health Risks:
Biofilms can cause health issues, such as dental plaque leading to cavities and gum disease. Various diseases with no known etiology can all be linked to biofilms. It can also impede the immune system from removing issues that otherwise would be addressed. In summary, biofilms are like microbial cities—sticky, cooperative, and sometimes a bit troublesome!
