Motility and chemotaxis play a crucial role in the ability of Sinorhizobium meliloti to nodulate its host, alfalfa. Swarming is a form of bacterial translocation, generally dependent on flagella, that involves cell differentiation and is characterized by a rapid and coordinated population migration across solid surfaces. This kind of active motility, mostly found in pathogenic bacteria in which it plays an important role in the colonization of natural environments, has not yet been described for any member of the family Rhizobiaceae. Although the pathways of signal integration are still poorly understood, there is evidence showing that extracellular chemical signals, physiological parameters as well as surface contact provide stimuli triggering swarm cell differentiation (Fraser, Hughes 1999).
Was this article helpful?