Quorum Sensing and Microbial Biofilms

Abstract

For a long time bacteria were believed to exist as unicellular organisms; however, it is now realized that in nature bacteria are more often found clustered in communities. Within these communities, bacteria are capable of coordinated activity through the use of a sophisticated intercellular communication mechanism called quorum sensing (QS). The capacity to behave collectively as a group has obvious advantages, for example, migration to a more suitable environment/better nutrient supply or adopting a more favourable mode of growth such as sporulation. Recently, QS was discovered to play a role in the formation of biofilms. This latter phenomenon will be the focus of this chapter as we review our current understanding of how QS affects the complex processes of biofilm development. With respect to intercellular communication and biofilms, Pseudomonas aeruginosa is one of the most intensely studied organisms, and therefore, much of this chapter will concentrate on this bacterium.