Bacteria communicate with chemical languages that allow them to synchronize their behavior and thereby act as multi-cellular organisms. This process, called quorum sensing, enables bacteria to do things they cant do as a single cell, like successfully infect and cause disease in humans.
The 41-year-old Bassler ~ a professor of molecular biology, winner of a 2002 MacArthur Foundation genius award, and occasional actress, dancer and singer ~ studies bacteria and how they communicate among their own kind and with other species. Quorum sensing, as this phenomenon is called, is a young science.
If it all holds up, the implications are enormous. Quorum sensing offers a way to think about evolution.
As Bassler puts it, “You can either make them deaf or you can make them mute.”
She also discovered something surprising. If she knocked out those two genes and put the altered V. harveyi in mixed company ~ that is, around masses of different species of bacteria ~ it glowed. “So I knew there was a second system,” Bassler remarks. Bacteria “don’t have enough room in their genome to be stupid, so there had to be a separate purpose for this system.”
The foreign bacteria were emitting something that V. harveyi responded to. Bassler called that something autoinducer two (AI-2). In 1994, as the field of quorum sensing was coming alive, Bassler moved to Princeton. Over time, she and others showed that quorum sensing initiates the release of toxins by bacteria such as V. cholerae. And they found that every bacterium they tested has its own personal autoinducer, the one it uses to communicate with its own kind.
Some scientists are also concerned that aspects of quorum sensing ~ but not Bassler’s findings ~ have been slightly overinterpreted.
“Do bacteria want to communicate with each other, or is it just by accident?” asks Stephen C. Winans, a microbiologist at Cornell University. “This idea has taken hold that these bacteria want to communicate with each other. It may be just too good to be true.”
Bassler’s drive ~ her friend and former mentor Silverman describes her as “intensely motivated,” “on a quest” and “just fierce” ~ suggests that she will hear bacteria’s every last word. For the time being, she remains focused on understanding AI-2. “I want it all to be one thing, so I am sure that is wrong,” she says.
“I want it to be one thing because that is better if you want to make a drug, right?” Bassler is one of several quorum-sensing researchers working with companies to develop drugs. In 1999 she formed a company called Quorex with a former colleague from Agouron. Although her involvement is limited at the moment, she is hopeful that the start-up will find new antibacterials.