Session 8: Discover- Bonnie Bassler

Her goal is to convince us that bacteria can talk to each other:

They are the oldest living organisms on the earth
The are single cell
They have limited genes
They grow and divide and grow and divide

We are covered in bacteria and minimally our own genes. We’re about 99% bacteria. They keep us alive by fighting attackers, they break down our foods etc. They get bad press for the few that make us sick.

But how do they do ANY of this?

The clue to explain this is a bioluminescent marine bacterium. When they are alone they make no light, but when in a community they light up.

They speak in a chemical language. They emit a molecule (imagine a hormone), a sort of radio call into the air waiting for a response. Then they get ping back and when there are enough pings they cacophony alerts them to turn on.

Since a squid hunts at night it uses the moonlight in shallow water, but to avoid a shadow they need light to shine below them—the bioluminescent bacterium. Then during the day the squid goes down below, hides and releases the bacterium

Signal producing/receptor proteins make bacterial quorum sensing. The must work in concert to be effective. The molecules of communication are similar but specific so they speak only to each other.

They must also be able to communicate interspecies as well. Bacteria are multi-lingual with a second language molecule, a generic kind.

Now, what if we made bacteria that couldn’t speak? Then we wouldn’t need antibiotics to wipe out bacteria en masse, but just made certain bacterium deaf and dumb to each other with an anti-quorum sensing molecule.

Remember these things into quorum sensing in bacteria:
Talk to each other
Multi—cellular
Can distinguish self from other
Develop strategies to impede/improve quorum sensing

ALSO we can help beef up conversation in quorum sensing amoung good bacteria.

Ends with a plug for the students. The engine of learning and understanding is done by young people between 20-30 years old. Remember that!