Quorum Sensing in Bacteria; Cell-to-cell Communication and Signaling Mechanism.

Abstract

Quorum sensing is a signaling mechanism in which bacteria coordinate with one another through chemical mediators. This system allows bacteria to communicate with the help of signals and work together to enlarge population density. The actual mechanism of quorum sensing depends on the secretion of auto-inducers (chemical signals) which are tiny molecules discharged by bacteria. In gram-positive bacteria, the chemicals that serve for quorum sensing are auto-inducer peptides (AIPs). At the same time, gram-negative bacteria induce quorum sensing by acylated homoserine lactone (AHL) molecules. In the beginning, the concentration of autoinducers boosts relatively and the population becomes dense. When the level of auto-inducers arrives at a threshold concentration, the transcription of genes occurs. The expression of genes exhibits characteristics such as biofilm development, symbiotic relationships, and pathogenic factors. The assortment of quorum sensing enables bacteria to adapt to various environmental developments. To lessen the intensity and virulence of quorum sensing, a strategy of quorum quenching is formulated. A set of enzymes is used to decrease the activity of quorum-sensing regulated bacterial species. Besides all this, quorum sensing has vast applications in the fields of medicine and agriculture. It is used to synthesize antibacterial treatments (quorum sensing inhibitors QSI) to disrupt various bacterial infections. In the agricultural department, quorum sensing can improve plant-bacteria symbiotic associations, enhancing crop development and protection against disease.  The manipulation of bacterial interactions can provide various benefits to modern scientific research and applications. This review is a brief overview of the mechanism of quorum sensing in bacteria which describes the aspects of Quorum sensing.