"Directed evolution" may save our polluted planet. At least, chemical engineer Dr. Frances Arnold sees it that way.
The recent National Medal of Technology and Innovation recipient is credited with pioneering the technique of directed evolution, a method used to engineer proteins or evolve certain organisms, leading to the revolutionary production of renewable fuels and chemicals, among other results.
Could the developments in Dr. Arnold's lab change our future? Check out the video above and/or click the link below for her perspective. And join the conversation by leaving your thoughts in the comments section at the bottom of the page. Come on, talk nerdy to me!CLICK HERE FOR FULL TRANSCRIPT
FRANCES ARNOLD: All this power that I have is both a blessing and a curse because in the past the breeder would take two cats and make more cats with it, but I’m the one who now has to decide whether I breed genes from fungi and fishes. Or I sprinkle in a little bit of bacterial DNA there, and I don’t really know what the rules are yet.
CARA SANTA MARIA: That’s Dr. Frances Arnold. She's a professor of chemical engineering, bioengineering, and biochemistry at Caltech. She developed a process called directed evolution. As the name implies, she directs evolution. Specifically, she directs the evolution of DNA sequences in living things to make enzymes, a type of protein that has tons of useful applications.
FA: I can make bacteria for example that will convert sugar into gasoline.
CSM: Or lots of microorganisms. They have these tiny molecular machines that took millions of years to evolve, and they do things that are useful--but not necessarily to us. What if she directed them, through a sort of quick-fire, forced evolution, to work on our payroll? Take yeast. They usually make alcohol--the kind you find in beer and wine. But....
FA: I re-engineer the yeasts, so instead of making ethanol, which is great for drinking but not so much for driving, I convince those yeasts instead to make something like isobutanol. Isobutanol’s got two more carbons than ethanol, and that mixes just beautifully with your gasoline. In fact, you can put isobutanol straight into your car and it will run.
CSM: Think this sounds extreme? That Dr. Arnold is "playing God?" I personally don't believe in God, but that's beside the point. I think we're already "playing God" by burning fossil fuels that've been trapped in the Earth for millions of years.
FA: We’re just pumping all of this wealth out of the ground, and it belongs to our children and their children. We don’t have the right to do that. But we’re doing it. We need to stop doing that, we need to find alternatives, and I’d like to think that biology, which lives sustainably on this planet, could provide a model for doing that.
CSM: So how exactly does Dr. Arnold direct evolution?
FA: We have all these wonderful tools where I can take for example a polymerase, that’s an enzyme that copies DNA and replicates it, making multiple copies. Now if I make that polymerase a little bit drunk, every once in awhile, it just inserts the wrong base and it makes a fuzzy copy. So I can control how fuzzy the copies are and I can make scads of mutated copies of DNA, that all look kind of like what I started with, but have varying levels and controllable levels of randomly introduced mutations.
CSM: And once she figures out what those mutations do, she can figure out how to use them to our advantage.
FA: The applications for biology, for using biological solutions in our everyday lives, go everything from baking bread using yeasts to laundry detergents to making better pharmaceuticals to making proteins that can be used to treat diseases, to imaging in the brain (we make new proteins that can be used to image how you’re thinking and what you’re thinking about inside of a living brain). There are dozens of interesting applications.
CSM: President Obama recently awarded Dr. Arnold the National Medal of Technology and Innovation for her efforts. And in 2011, she was the first woman ever to receive the Draper Prize in engineering. Let me know what you think about the amazing work this inspirational woman is doing. Come on, talk nerdy to me!