Bacteria communicate with each other using quorum sensing
Humans talk to one another. Other animals, like birds and whales, also use sound to communicate. But in the bacterial world, conversation is chemical. This chemical communication, or ‘quorum sensing’, is what allows bacteria to synchronise the type of coordinated attack that will leave you feeling sick.
Since the discovery of quorum sensing several decades ago, scientists have realised that all bacteria use it to communicate all the time – within their own population and with other populations of bacteria within the same community.
Quorum sensing is based on population density. Bacteria release communication molecules that float away when the population is small.
Image taken by E Nelson and L Sycuro, and provided by E Ruby
A curious light-producing bacterium called Vibrio fischeri uses quorum sensing molecules to sense when its population has grown to a certain size, at which point all the bacteria in the population switch on their lights. The bacteria are symbiotic, living in an organ of the Hawaiian bobtail squid (pictured above). The bacteria’s luminescence prevents these squid from casting shadows on moonlit nights, which in turn helps them avoid predators.Lead image: