Team:UNIFI/Biological principles
Biological principles
Bacterial communication
Bacteria are unicellular organisms, but many of their biological activities are strictly dependent on the number of cells that are present in the colony. In fact, bacteria have developed some sorts of communication, based on cell-to-cell signaling and response, which allows them to activate specific functions only when the colony is big enough. This phenomenon is known as “quorum sensing”: the mediator is a self-generated diffusing molecule, whose accumulation in the surrounding environment determines a chemical gradient; the cells in its proximity respond enhancing the production of the mediator and activating a positive feedback, resulting in a coordinated response.
The first example of quorum sensing was discovered in Vibrio fischeri, in which the autoinducer is an N-acylhomoserine lactone (AHL), specifically N-(3-oxohexanoyl)homoserine lactone (3O-C6-HSL), and the response consists of the activation of bioluminescence; but there are many other activities that show a similar regulation, such as biofilm formation, virulence and sporulation. With our project, we aim to obtain different bacterial populations who, growing in the same environment, can activate a similar response: the different populations are engineered with different feedback boxes. When the mediator is present, translation is activated and the cross-talk makes the system auto-regulative.
References:
Brenner's Encyclopedia of Genetics (Second Edition), 2013, Pages 25–27, Quorum Sensing, S.P. Diggle, P. William
Team Unifi
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