What is quorum sensing and its importance for bacteria?
Quorum-sensing allows individual bacteria within colonies to coordinate and carry out colony-wide functions such as: sporulation, bioluminescence, virulence, conjugation, competence and biofilm formation.
What is quorum sensing?
Quorum sensing (QS) is a bacterial cell–cell communication process that involves the production, detection, and response to extracellular signaling molecules called autoinducers (AIs).
How does an Autoinducer allow quorum sensing?
Autoinducers are signaling molecules that are produced in response to changes in cell-population density. As the density of quorum sensing bacterial cells increases so does the concentration of the autoinducer.
What is a biofilm what are its features and importance?
A biofilm is an assemblage of surface-associated microbial cells that is enclosed in an extracellular polymeric substance matrix. Van Leeuwenhoek, using his simple microscopes, first observed microorganisms on tooth surfaces and can be credited with the discovery of microbial biofilms.
What is one characteristic of a biofilm?
Biofilms appear to show aspects of both solids and liquids—much like slug slime—and fall into a category called “viscoelastic.” However, as biofilms collect sediment, or become scaled with rust or calcium deposits, they become less fluid and more like a brittle solid.
What are autoinducer peptides?
Peptides. Gram-positive bacteria that participate in quorum sensing typically use secreted oligopeptides as autoinducers. Peptide autoinducers usually result from posttranslational modification of a larger precursor molecule. In many Gram-positive bacteria, secretion of peptides requires specialized export mechanisms.
What are three differences between gram-positive and Gram-negative cells?
Gram positive bacteria have a thick peptidoglycan layer and no outer lipid membrane whilst Gram negative bacteria have a thin peptidoglycan layer and have an outer lipid membrane.