arnold_frances.jpgFirst, I'll let you explain what you mean by "evolutionary design of biological systems." What kind of methods do you use?
I figured out what nature figured out quite a while ago. If you want to redesign biology, say, to make it solve some human problems, the best thing is not to sit down and try to pencil it out before hand, but to actually try to breed molecules instead. That is, admit that we know very little about how they truly function at the molecular level and let an evolutionary algorithm take over for you in the design.

I see in your CV that you earned your bachelor's degree in mechanical and aerospace engineering and you went on to work as a research engineer in solar energy. What inspired the transition to chemical engineering and biological systems?
I was working on alternative energy when Carter was president, and we actually had a goal of 20% renewable energy by the year 2000. Unfortunately, we had a change of administrations, and when President Reagan came in, I decided I needed a new career. I went into the brand new field of biotechnology, and I'm really glad I did, because now I've come back to renewable energy research with much more powerful tools than we had 30 years ago.


Much of your work involves cytochrome P450 enzymes. What's your interest in this enzyme?
My little brother, Eddy, who got me interested in biochemistry, told me, "This isn't an enzyme - this is a city." It's so complex, it does so many interesting things. One of the things it does is stick an oxygen atom into an unactivated carbon-hydrogen bond. That may not sound impressive, but that's something that's really hard to do.


Your lab is working with yeast to engineer cellulases and cellulolytic enzymes for manufacturing biofuels, but in a 2008 review article, you argue that ethanol, in your words, "isn't even the most attractive of fuels." Why engineer cellulases for biofuels if you don't think ethanol is worthwhile?
If you think about renewable energy or renewable fuels coming from biomass, you've got two problems. One is, how do you extract the sugars out of waste products and non-food sources? That's where the cellulases come in, because those are the enzymes that can break down the cellulose to sugars. The second half is to figure out what do you make from those sugars. And right now we make ethanol, because we've been doing it for 10,000 years or so and we know how. But with the technology we have, with the knowledge we have to create new metabolic pathways in microorganisms, why would you stick to ethanol? Why not make something that looks a lot more like the hydrocarbons that we currently use? I'm interested in developing whole new metabolic pathways to make things like isobutanol, which can be converted into hydrocarbons.


I know that when your line of work is very technical, it can be difficult to explain to a non-scientist what exactly, you do for a living. How do you describe your work to someone you meet at a cocktail party, for example?
I love the fact that I get to play with evolution, so I tell people about Darwin and say that I'm practicing Darwin's principles with molecules. The other thing is, everyone's interested in climate change and where our is energy coming from, so I also tell people that I'm working in alternative energy and trying to provide a renewable source of fuels.

What is your favorite microbe?
I do most of my work torturing them rather than studying them, so my favorite microbe is one that does my bidding easiest, and that happens to be good old E. coli.


If you could name a new microbe right now, would you name it after yourself? If not, how would you name it?
It's unlikely that I'll discover a new microbe, but I might create one, or at least create some interesting new components. I probably wouldn't name it after myself though - I might name it after Darwin, since he gets the credit for inspiring me.


What advice would you give students about life as a microbiologist (chemical engineer?) working in academia?
This is a great career - it's incredibly flexible. And just imagine how nice it is to be able to come in every day and meet brilliant young people and be able to do what you find fascinating.


Tell us something about you that most people don't know.

I love to travel to faraway places - places that are hard to get to and difficult to travel in. I took my three sons around the world for a whole year about five years ago.