Beautiful Biofilms
At OU-Norman, I will be meeting a microbiology class to talk about biofilms. I know it’s hard to believe how beautiful a biofilm can be, especially when it’s growing on your teeth. But this one pictured above is a marine bacterium Marinobacter hydrocarbonoclasticus SP17 growing on alkanes (hydrocarbon pollutants). It’s not only beautiful, it’s doing us service by cleansing our oceans–and as we all know, our oceans desperately need cleansing.
How do biofilms grow? Surprisingly, there is a pattern common to many biofilms formed from many different species, often multiple species in one biofilm. First the swimming bacteria decide to settle (not sure how; sometimes they communicate with each other by chemical signals called quorum sensing.) Then they stick their flagella onto a substrate, and start to pile up next to each other. The cells grow in a monolayer, and start coating themselves with polysaccharide (long chains of sugars–sticky). In the advanced stage, the biofilm builds up towers of semi-dormant cells with nutrient channels inbetween. Finally, the towers grow buds of motile “planktonic” bacteria that escape to go out and start new biofilms elsewhere.
The process can be deadly, especially if it happens inside your lung when you have cystic fibrosis. But the same Pseudomonas bacteria–in a very different setting–can make a sugar polymer called alginate, a biodegradable material that we can harvest and use for all sorts of things, like dental products and artistic sculptures.
What would you like to do with biofilms?
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Ultraphyte 
Making a biofilm computer would be cool. I didn’t realize alginate was a biofilm. Thanks!
Alginate is one of the polymers made by Pseudomonas to cement cells together in the biofilm. A biofilm computer could be interesting–also as a model for self-assembling nanocomputers.
I would very much like to prevent biofilms from forming on my teeth–why is that so difficult?–and why is cystic fibrosis so hard to cure?
High School answer – because cystic fibrosis is a genetic disease rather than having a vector.
I believe there is a TED video of biofilms being grown and used as clothing.
I’m looking forward to the talk tomorrow at OU and interested in quorum sensing and how exactly bacteria communicate!
Hope you enjoyed it. I’ll blog more on bacterial communication later.