Bacteria quorum sensing, a means of communication

13 FEBRUARY 2026

Renowned molecular biologist Bonnie Bassler, Professor at Princeton University, delivered a lecture titled “A chemical language that enables communication between diverse organisms”, in Bengaluru.
She described bacteria as “magical microbes” that not only cause disease but also sustain life.
She highlighted how bacteria communicate through a process called quorum sensing.

Quorum Sensing

Bacteria can “talk” to each other using chemical signals.
They are multilingual, meaning they can communicate across species.
When enough bacteria gather, they coordinate behavior collectively.
This communication system controls virulence (disease-causing ability), helps bacteria act as a group and shapes evolutionary biology.

The Mechanism of Quorum Sensing

The process operates as a “bacterial roll call” and generally involves the following steps:

Production: Individual bacteria constantly produce and release small signaling molecules (autoinducers).
Accumulation: As the bacterial population density increases, the concentration of these molecules in the surrounding environment builds up.
Detection: When the concentration reaches a critical threshold, the autoinducers bind to specific receptors on or in the bacteria.
Response: This binding triggers a change in gene expression, leading to the synchronization of group behaviors.

Anti–quorum sensing therapies

Instead of killing bacteria with antibiotics, Prof. Bassler suggested developing anti–quorum sensing therapies
These therapies aim to:

Block bacterial communication
Prevent bacteria from turning virulent
Reduce antibiotic resistance risks
She cited Vibrio cholerae, the bacterium that causes cholera, as an example of a harmful organism whose communication system could be targeted.

Mutualism of Squid and Vibrio fischeri

She contrasted cholera bacteria with its “cousin” vibrio fischeri – a bioluminescent bacterium that lives in symbiosis in the photophore (light prodcing organ) of the Hawaiian bobtail squids.
The squid hunts in moonlit waters.
As predators track its shadow, vibrio fischeri glows beneath the squid and removes the shadow — making the squid invisible.
This is a stunning example of mutualism and bacterial cooperation.