Biofilms (brief introduction)

In 1684, Anton van Leeuwenhoek took a portion of tartar from his teeth and discovered the presence of certain “animalcules” embedded within it forming a sticky association; however, it was not until the early 1900’s that microorganisms attached to surfaces were recognized, not until the 1970’s that biofilm formation was documented for bacterial communities, and not until the 1980’s that it was recognized that bacteria along with other microorganisms could attach to surfaces and organize in highly complex structures. Today, biofilms are defined as complex heterogeneous microbial communities attached to surfaces or associated with interfaces by a self-produced extrapolymeric matrix.

Biofilms can be found in a great variety of environments in which non-sterile conditions are present: natural, clinical or industrial environments. The most important reason why microbes integrate into biofilms is for establishing different strategies to adapt to unstable environmental conditions; when the latter are unfavorable, a typical stress response is induced. In most natural environments, the association with surfaces or interfaces is their predominant lifestyle, because it provides a favorable microenvironment where the cells will not be stress-compromised by free displacement and shear stress, and although each cell in the biofilm has its own stress response pathways, living in populations provides supplementary mechanisms of survival, being the most patent advantage their heterogeneity.

Biofilms are also important for microorganisms due to the protection they offer against antimicrobials, phages, immune systems, desiccation, toxins, UV radiation, wash-out, high dilution rates, predators and other stress factors. Biofilms facilitate phenotypic diversity in microbial populations, enhance nutrient access and availability, promote a cooperative metabolism, facilitate horizontal gene transfer and uphold a cellular communication mechanism known as quorum sensing.

References:

Dominguez-Benetton X. (2007). PhD Thesis, Mexican Petroleum Institute, Mexico.

~ by koxinelle on February 18, 2007.