What is quorum sensing in bacteria?

Quorum sensing in bacteria is a communication process that allows bacteria to monitor their population density and subsequently adjust their gene expression in response to changes in cell concentration. This mechanism works through the release and detection of signaling molecules called autoinducers. When the bacterial population reaches a certain density, the concentration of these signaling molecules increases, leading to a coordinated response among the cells. This can result in various changes in behavior, such as the expression of virulence factors, bioluminescence, biofilm formation, or the production of secondary metabolites.

The ability to adjust gene expression based on cell density allows bacterial communities to behave in a more coordinated manner, which can enhance survival in different environments and can also lead to the establishment of complex behaviors that are beneficial for the population as a whole, such as forming biofilms or launching attacks on host organisms.

Other options do not accurately reflect the concept of quorum sensing. While bacteria do adjust their metabolism based on nutrient availability, this process is not specific to quorum sensing. Detection of environmental toxins and reproduction among bacteria also occur through different mechanisms unrelated to quorum sensing.