Amphiphilic Lipids, Signaling Molecules, and Quorum Sensing

Abstract

Many bacteria communicate with each other through the action of diffusible signal molecules, a process that has been termed quorum sensing (QS). QS acts to regulate diverse processes in different bacteria, to include the formation of biofilms, cellular differentiation, synthesis of antibiotics and other secondary metabolites, and the production of virulence factors in pathogens. Many bacteria use amphiphilic lipids of different chemical classes as signal molecules. N-acyl homoserine lactones, cis-2-unsaturated fatty acids, methyl esters of hydroxylated fatty acids, and tridecanone derivatives have been described in different Gram-negative organisms and gamma-butyrolactones in Gram-positive streptomycetes. A diverse range of mechanisms for perception and transduction of these signals has been described. Here we review these different signals, their mode of biosynthesis, and transduction pathways before going on to discuss interference of QS as a strategy for the control of bacterial disease.