Xavier, KarinaValente, Rita Susana da Silva2014-07-312014-05http://hdl.handle.net/10362/13040Dissertation presented to obtain the PhD degree in BiologySince scientists realised that microorganisms are almost never alone in natural environments, but are actually part of large and diverse communities, the molecular mechanisms underlying bacterial interactions have been intensely studied. Cell-to-cell communication is an important bacterial process where a self-produced molecule (autoinducer) is released into the extracellular medium where it accumulates. At a certain threshold, the autoinducer is recognized by the surrounding bacteria that respond with a synchronized change in gene expression.(...)engdoctoral thesis101284250