∞ generated and posted on 2016.12.15 ∞
Surface-associated conglomerations of microbial cells that are encased to greater or lesser extents within extracellular polymeric substances.
|Biofilms are ubiquitous, coating most surfaces that are in contact with both water and microorganisms, allowing for microbial adherence to a single location, cooperation among cells, and protection from immune systems, antibiotics, and various environmental degradants as well as desiccation.|
Biofilms often consist of multiple species, though individual species often can be found as distinct microcolonies within the larger biofilm.
Figure legend: Biofilms are tangled masses particularly of surface-adherent cells, typically bacteria, that are encased within various secreted substances that collectively are referred to as extracellular polymeric substances or EPS. Note that shown is an illustration of a biofilm-like structure rather than a microscopic image of an actual biofilm.
The following video illustrates biofilm formation:
It is thought that a substantial fraction of bacteria, including bacterial pathogens, are normally found existing within biofilms rather than as free-floating (planktonic), individual cells.
From Kolton (2010):
Biofilm formation is a developmental process in which bacteria undergo a regulated lifestyle switch from a nomadic unicellular state to a sedentary multicellular state where subsequent growth results in structured communities and cellular differentiation.
The above is in quotation marks in the original. A reprint of this wonderful article can be found here.
The following video illustrates biofilm formation and persistence in hospital water supplies:
Removal of biofilms (below) from infected, open wounds; not for the excessively queasy!