Applications
Quorum sensing systems can be an innovative tool, enabling the design of a complex system with a cascade of controlled reactions. A good use of this will enhance the success of systems that utilize bacteria as biofactories. One straightforward and already implemented application would be of coordinating single cell genetic behaviour based on the population's overall state, which means robustness of behaviour along the population, a much needed factor for other applications. Other applications, though, have their success impeded by the amount of crosstalk in quorum sensing systems.
Such is the case for synthetic communities, where you can design division of tasks between strains of bacteria, whose population growth could be mediated by quorum sensing. The strengths of two very different strains could be harnessed at the same time, while avoiding metabolic burden and complicated molecular biology tests and procedures to try and force E.coli to produce something unnatural to it. Quorum sensing also brings interesting possibilities to the concept of biological logic gates.
One possibility that came to our minds when studying quorum sensing was the idea of using incoherent feed-forward loops (IFFLs) to diminish crosstalk between pathways. The way this loops work is by an element of a circuit having a negative indirect effect (repression) over something which already suffers a positive effect (activation) by the first element. This way, the effects could cancel out and negate the effect of the first element to the second.
At first this may seem paradoxical, but it could be exactly the right thing if you want to make two elements independent of each other by eliminating unwanted interaction. Quorum sensing suffers from this, with crosstalk as a very unwanted interaction. We hypothesized such a circuit, and came to the conclusion that a double-repression system would be needed, to counteract the repressor hindering the other system's native expression instead of just the crosstalk.
All of these examples are only a snippet of all the applications for this incredible mechanism. With more understanding it's secure to say that several areas of the society will benefit from works with quorum sensing!