Quorum
sensing is the regulation of gene expression in response to fluctuations in
cell-population density.In a population of bacteria, each individual
bacterium is capable of producing a signaling molecule (inducer) and each
bacterium also has a receptor for the inducer. When the inducer binds to the
receptor, it activates the transcription of certain genes, including those
responsible for the synthesis of the inducer itself. As the bacterial
population grows, the concentration of the inducer in the surroundings
increases, causing more inducer molecules to be synthesized. Gram-negative bacteria use acylated
homoserine lactones as autoinducers, and Gram-positive bacteria use processed
oligo-peptides to communicate. AHL-mediated quorum sensing
is one of the best characterized cell-to-cell communication mechanisms.More
than 70 bacterial species are known to produce AHL-type quorum-sensing signals,
with many producing multiple AHLs. Quorum sensingwas originally discovered in
the luminescent bacterium Vibrio fischeri. In several bacteria,
disrupting quorum sensing adversely affects biofilm formation. Insect species
use quorum sensing to detect the nest. A very interesting example is that of
the small ants of the species Temnothorax albipennis, which typically nest
in rock crevices. The most important implication of all this for human beings
is that once we understand how bacteria talk, we can find ways to block their
communication.
Name of the Student : Binisha A
Reg No: 1741210049
Batch: M.Tech II Year
Name of the Guide : Dr. B.Usha