A switch between life forms
Oeiras, 17.02.2015
Depending on environmental conditions, bacteria may live as free cells or form communities, called biofilms. The switch between these two life forms is controlled by a specific protein – BolA. This is the main conclusion of a study conducted by researchers from the Lab of Control of Gene Expression, which is published today in mBio, an open access journal from the American Microbiology Society.
Biofilm formation is an important factor to consider when dealing with bacteria, in infections or in industrial settings, since this type of organization makes bacteria more resistant to antibiotics and detergents. Typical examples of biofilms include dental plaque and slime deposits in tanks and pipes. But biofilms can form on almost any surface and allow bacteria to resist together to an adverse condition. Through a complex process, bacteria adhere to the surface and to each other, forming a kind of slime, and coordinate their behaviour.
Though a series of genetic manipulations in the lab, researchers noticed that when BolA was turned off, bacteria kept their flagella and no biofilms were formed. On the contrary, the activation of BolA triggered a cascade of reactions that interrupted flagella formation and started the production of the proteins and polysaccharides necessary for biofilm formation. Researchers further demonstrated that BolA is a protein with high affinity to DNA, thus marking BolA as a new bacterial transcription factor.
While the study was conducted in Escherichia coli, the results are easily extrapolated to other Gram-negative bacteria, such as Legionella and Salmonella. Cecília Arraiano, who coordinated the study, believes that “understandingthe role of BolA as a molecular switch between planktonic and sessile life is an important step to control biofilme formation in potential medical ou biotechnological applications”.
Original Article
mBio (2015) vol. 6 no. 1 e02352-14
BolA Is a Transcriptional Switch That Turns Off Motility and Turns On Biofilm Development
Clémentine Dressaire a, Ricardo Neves Moreira a, Susana Barahona a, António Pedro Alves de Matos b, Cecília Maria Arraianoa
a – ITQB
b - Egas Moniz—Cooperativa de Ensino Superior
