quorum sensing


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quorum sensing

a phenomenon in bacteria that limits certain behaviors to occurring only above a certain population density.

quorum sensing

n.
A phenomenon in which a population of bacteria produces and responds to intercellular chemical signals whose concentration indicates the density of the population. When the density reaches a certain level, genes are expressed that allow for coordinated group behavior, as in bioluminescence or the formation of biofilms.

quo·rum sens·ing

(kwōr'ŭm sens'ing)
A process whereby bacteria communicate by means of extracellular molecules called pheromones.

quorum sensing

a process in which unicellular organisms secrete signal molecules that influence the behaviour of a population of identical organisms, but only when the density (number of cells per unit volume) of that population is above a certain level. Cells sense the concentration of the secreted signal molecule, often a homoserine lactone, which tells them how many other cells are in their environment. When a threshold concentration of the signal molecule is reached, the population density has achieved a critical level or quorum, and quorum-dependent genes are expressed by auto induction. A given species can produce a range of autoinducer signal molecules, which regulate expression of genes governing characteristics that are only exhibited above this critical population density Thus specific characteristics may be displayed by cells present at high density, but not by the same cells when present at low density Examples of quorum sensing include, bioluminescence of Photobacterium fischeri when occurring as a SYMBIONT in high density populations, but not when free-living in low density populations; promotion of COMPETENCE for TRANSFORMATION in Bacillus subtilis, when present at high density; and production of VIRULENCE factors in Pseudomonas aeruginosa.
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Quorum sensing control wells (eight replicates) contained cell-free culture supernatant (100 [micro]l) obtained from P.
The findings indicate that Ruegeria KLH11 uses quorum sensing in a previously unsuspected way, to activate "a dispersal mechanism that promotes the uniform distribution of these bacteria in the local environment when the population becomes too dense," says coauthor Clay Fuqua, a professor of biology at Indiana University Bloomington.
According to the scientists, micro-organisms inhabiting these mats produced quorum sensing inhibitors under natural conditions.
Recent quorum sensing investigations have demonstrated that some bacteria, plants and animals are capable of producing compounds that can disrupt the bacteria's ability to communicate and thereby disable bacterial growth and the ability to become pathogenic.
In some bacteria, quorum sensing triggers the production of enzymes that catalyze light-producing reactions.
Of significance is the role that quorum sensing plays in pathogenesis.
How bacteria talk to each other: Regulation of gene expression by quorum sensing.
SAN DIEGO -- Pico Pharmaceuticals today announced a publication in the journal Nature Chemical Biology that supports a novel mechanism for the inhibition of quorum sensing pathways in bacterial pathogenesis.
Quorum sensing Escherichia coli regulators B and C (QseBC): a novel two-component regulatory system involved in the regulation of flagella and motility by quorum sensing in E.
From a technical perspective, the ajoene blocks the communication system - known as Quorum Sensing - in the bacteria, which is used for purposes including creating infection.
The approach in BYEFOULING is to tackle the different stages of the biofouling process using innovative antifouling agents, covering surface-structured materials, protein adsorption inhibitors, quorum sensing inhibitors, natural biocides and microorganisms with antifouling properties.