Specifically, the researchers looked at the way in which bacteria communicate with each other to organize themselves into a biofilm. The organisms send out the call to have other bacteria join their community through signal molecules called autoinducers in a process known as quorum sensing (QS). If those signal molecules could be blocked, the researchers reasoned, then the biofilm wouldn't be able to form. It's akin to keeping people from forming a mob in the dark by not letting them shout out their location.
The proteins that can shut down quorum sensing are known as quorum quenching (QQ) proteins and, to learn more about them, the researchers turned to the natural world, taking samples from sources including seawater, glaciers and jellyfish. What they found was that there's a large number of QQ proteins in marine environments – more than what they found on land.
"As the oldest ecosystem, the marine system – including the oceans, water or algae – is incredibly rich in new, undiscovered substances," said said Ruth Schmitz-Streit, a professor from the Institute of General Microbiology at Kiel University." It offers a huge potential regarding biological activities and QQ mechanisms."
In particular, the researchers identified a QQ protein known as QQ-2 as an especially effective communication disruptor.
"This protein is very robust and can prevent many different types of biofilms," said Kiel's Nancy Weiland-Bräuer.
Whereas previous research had found QQs to quelch very specific bacterial communication molecules, QQ-2 was found to be more of a generalist. "The QQ-2 protein is orientated towards a 'universal language,' and can disrupt the communication of different bacteria," added Weiland-Bräuer. "This makes it a 'general troublemaker.'"
The researchers hope that their work can lead to the development of biofilm-busting techniques that can help keep medical facilities clear of disease-causing slime.