Currie: 'The enzymes [ants use] to break down plant cell walls... could be integrated into an industrial process to make biofuel.'
The long, windowless room is uncomfortably warm and humid. The counters and shelves are filled with Tupperware boxes, like the ones people use to store sweaters under their beds. But these boxes are filled with gray mold and crawling with leaf-cutter ants.
Don't run for a can of Raid. Instead, cross your fingers and hope that the keeper of these ants, UW-Madison associate professor of bacteriology Cameron Currie, can tease secret recipes for cheap biofuel out of these teeming ant tunnels.
Currie, 39, a tall and soft-spoken Canadian, bends over an open box, stares intently for a moment, then dips a finger into the spongy mass and scoops out something that looks like a couple of gray jelly beans. It's actually an ant queen. The entire colony relies on her, and, as gas prices rise, we may be depending on her as well.
Leaf-cutter ants are some of the most successful animals on the planet. In the rainforests of South America, they rule. A single underground colony could fill a two-car garage, and the ants inside can outweigh an elephant.
They live by slicing up leaves and hauling them into underground chambers to feed the vast gardens of fungus they use for both food and furniture. In the process, each colony breaks down the cellulose of plant cell walls on a massive scale.
"The ants are doing what we'd like to be able to do," explains Currie. "If we discover the enzymes they are using to break down plant cell walls, those enzymes could be integrated into an industrial process to make biofuel."
The Department of Energy is banking on Currie's speculation. In 2007, the DOE decided to invest big in biofuels, funding three bioenergy research centers around the country, including the Great Lakes Bioenergy Research Center at the UW-Madison.
Steven Slater, associate director of the center's Wisconsin Bioenergy Initiative, heaps praise on Currie.
"Not every scientist has the intellectual horsepower and collaborative attitude that is critical in these big science projects, where you need a lot of people coming together to attack big problems. That's what the center is about, and Cameron is a really critical piece of that."
Currie's research is also generating national interest. He and his team were recently awarded the equivalent of $100,000 in genome sequencing services by Roche Applied Sciences. Roche, which has taken the sequencing world by storm in the last several years, screened 700 applicants worldwide, and Currie's team was one of just two to receive grants.
Science magazine has published Currie's research three times since 2006, and Nature ran an article last June. In December, the Discovery Channel spent a whole day filming in Currie's lab for Power the Future, which should air in late summer.
In January, Currie was awarded the Presidential Early Career Award in Science and Engineering. He is among 100 winners tapped this year by nine federal agencies as up-and-comers with the potential for innovative research at the frontiers of science who also shine in education and outreach.
"Technically, I did not get handed the award from Obama," Currie says, with his typical penchant for accuracy. "But we did visit the White House, and we did meet Obama. It was a bit surreal." When Obama walked into the room, says Currie, it was like a scene from a movie: "You could feel his incredible presence."
But there is a downside to all of this attention - it increases the pressure on Currie to deliver results.
"When you write a successful grant and get $2 million, you go 'Woo-hoo!' for about a minute," says Currie with a grin. "Then you realize you've just been awarded years of work and pressure."
Eyes on the prize
The U.S. Department of Energy funnels some $25 million into the Great Lakes Bioenergy Research Center, more than half of which is spent in Madison. About $400,000 goes to the ant research in Currie's lab. The center also funds and coordinates research with other national labs.
No one expects biofuels to completely replace fossil fuels, but they could be part of the answer, helping reduce greenhouse emissions and providing a renewable alternative. Research on some biofuels, along with other alternative energy sources, will likely pay off in the long run.
One issue that vexes budding biofuel efforts is whether croplands needed to feed hungry people should be used instead to feed our gas-guzzlers. The best biofuel options will have to prove their sustainability. And any biofuel solutions will have to address questions about both agricultural and environmental impact, such as which crops to plant and where to plant them.
"Our center is aiming not just to create new biofuel production processes, but to select the ones that are actually going to be beneficial to the environment," says Margaret Broeren, communications manager for Madison's biofuel center.
Enter Cameron Currie and his team of entomologists, computational biologists and microbial genomicists. Also, his teeming mass of ants.
Leaf-cutter ants have been growing their own food and converting cellulose into material they can use for 50 million years. That gives them a pretty good track record for sustainability.
Currie believes cellulose is being broken down in ant colonies through a multi-organism communal effort. Thus researchers in his lab are studying the interconnected community of ants, fungus and bacteria.
To this end, they are extracting and sequencing the DNA from each member species. The Roche Grant will allow Currie's team to do 10 gigabases of genome sequencing, which is equivalent to the size of a complete genetic sequencing of three humans.
The goal of this genomics research is to find the set of genes from the various species within the colony that relates to the enzymes chewing up plant cell walls. These genetic sequences can then be cut and pasted into other, more hardy bacteria that are known to survive and thrive by the industrial-sized vat-full.
If everything works out, these genetically modified bacteria could kick out enough enzymes to produce affordable biofuel. Lots of it.
"The center's mission is to do basic science that enables the production of biofuels from cellulose like wood and grass," says associate director Slater. "The major cost of making fuel from cellulose is breaking down the biomass into something that can be converted into a liquid fuel. We hope Cameron will be able to identify enzymes that can do that more efficiently."
Currie arrived in Madison in 2004, after a stint at the University of Kansas in Lawrence. A lifetime fan of the hapless Edmonton Oilers hockey team ("It's a little like being a Cubs fan"), he transferred some of his allegiance to the Badgers. He also plays hockey locally in a men's league. "You can't do that in Kansas," he notes.
Having settled in on Madison's east side, he feels at home there, hanging out on the Union Terrace and taking in symphony concerts at the Overture Center. But his ants are his priority, and he goes where he must to keep them in his sights.
Keeping it fun
Currie's lab feels as tropical as the colony storage room. Currie attributes it to all of the brain energy in the room. And although he grew up in Edmonton, one of the colder parts of Canada, "I've done so much tropical work collecting ant colonies that I'm sensitive to cold now."
The heat in the lab extends beyond the thermostat. "There's a warm family feeling," says Gabe Starrett, an undergraduate technician. "Ideas flow up and down, not just top down."
A lab technician, Sandye Adams, agrees: "The ants are running around. There are constantly new things going on. It feels like a playground. Cameron has created an environment where we can feed off the energy of everything around us, and he is at the middle of it. When he comes into the lab, it's like a kid in a candy store."
Garret Suen, a microbial genomicist and postdoctoral fellow in Currie's lab, did his undergraduate work in Calgary, three hours south of Edmonton. "The first time Cameron called me up to interview me, we spent the first half hour yelling at each other about hockey, and then we started talking science," says Suen. "Now we have a rule that we can't talk about hockey in the lab."
Training new scientists is one of Currie's favorite tasks, and he knows exactly what he wants to teach them: "Be passionate about what you study and have high expectations for your work, but don't take yourself too seriously."
As Currie sees it, being able to do scientific research is "not a right - it's a privilege. We take our science very seriously, but we keep a sense of humor because it's fun. It's fun! And we're more productive and successful when we keep it fun."
One of the things Currie enjoys most is the time he gets to spend in the tropics, looking for ants and the bacteria and fungi that sustain them (see sidebar).
"It's a different world," he says. "You can still discover new species of bacteria and fungi in your backyard in Wisconsin, but working in the tropics there are a lot more opportunities for discovery. There is just a higher density of new species and fascinating forms. It's a revved-up, action kind of situation."
Stalking ants in the rainforest has its hazards. Sometimes it's hard to tell who is hunting whom.
"The soldier ants are intimidating," Currie says. "They are large with huge heads and terrifying mandibles. They can bite through leather shoes."
Currie displays the side of a finger. "See this scar right here? I was moving ants from one box to another. She got on me and started chewing. My choice was drop the whole colony or let her go on chewing. I had to let her chew. By the time I put the ants down, she had taken five bites, and her mandibles are serrated. It was an absolutely clean gash. It bled for six hours."
Another time, he relates, "I put my pack down and went to get a closer look at some ants in the field. All of a sudden, I see a leaf-cutter carrying a blue leaf fragment. Then another. That was puzzling. There is not a lot of blue in the tropical rainforest. I realized it was the exact blue of my backpack. I ran over, but they had already cut 30 holes."
Challenging students
To get a safer look at leaf cutters in action, Currie has set up an ant colony in a huge display on the ground floor of the Microbial Sciences Building. It is part of a permanent mini-museum called Microbe Place. A thriving colony carries out its business within see-through walls, as workers transport leaf bits along clear tubing to their fungus gardens and then haul away waste to a dump chamber.
There is also a video camera trained on their inner recesses, with images displayed on the wall behind the colony. Currie plans to soon have this ant-cam available online, as an enticement to middle and high school students to consider science careers.
"Students will be able to go online and see the ant colony they are studying the genome of," says Currie. "We can use the fascinating biology of leaf-cutter ants to get them interested in genome research." A leaf-cutter ant board game, which teaches foraging strategies, is also in the works.
Currie believes it's critical to expose students at the high school and middle school levels to the research being done on campus.
"We need a lot of students interested in what we call the STEM area," he says, referring to the acronym for science, technology, engineering and math. "We need this to stay competitive as a nation, and also in terms of addressing pressing environmental issues. Anytime you can expose young students to interesting aspects of biology, that's useful."
In his own lab, Currie has about 15 undergrad assistants, more than the number of graduate students and postdoctoral researchers.
"We have an army of undergrads in here, and they are really talented," says Suen. "They will get publications out of this, and some of them are going to be lead authors. At the undergraduate level, that is phenomenal. This fosters a culture of science, which is something we are really invested in.
Rhonda Knapp, a Waunakee High School science teacher, spent last summer in Currie's lab as part of a program run by the biofuel center.
"The lab experience completely changed my mind about research," says Knapp. "I learned not to be afraid of the lab. Then I put the challenge to my students to look for cellulose degraders. They asked questions, and I didn't always know the answer, but we worked it out together. Kids learn a lot more when you are learning with them."
Knapp used this experience to develop bioenergy-related activities for her students.
"We brainstormed, and they brought in rotten produce from the back of their refrigerators," she says. "After all, the mold was breaking down cellulose. We isolated the cellulose degraders and grew them on a medium. Our goal is to take the cultures we grew back to Cameron's lab and see if there is anything of interest. This directly connects my students to university research."
As an undergraduate, Currie was interested in studying larger animals, like lions, but the ants caught his eye. He hasn't looked away since. While it's easy to look at an anthill and see a microcosm of our own society, Currie sees more. He sees productive farmers, fearless warriors, subtle biochemists, advanced educators and convincing ambassadors.
Ants: Farmers, warriors, ingenious adaptors
UW researcher Cameron Currie collects leaf-cutter ants in the rainforests of Panama and Costa Rica. Then he flies them back to Madison packed in a gym bag and stowed in the overhead compartment. Each walnut-sized starter colony contains a queen and some fungus, so he can pack as many as 80 colonies each trip. He hopes that studying these ants may lead to scientific breakthroughs in both biofuel and medical research.
Native to the rainforests, these ants could never survive a Wisconsin winter. That's just as well. They might not be good neighbors. In their home territories, they are the dominant animal, and they share traits with another dominant species we see whenever we look in the mirror.
Ants, like humans, are one of the few organisms on the planet that farm, growing fungus in a vast network of interconnecting underground tunnels. Their agricultural prowess has fueled the creation of massive colonies, larger than those of any other ants. They gobble up to 20% of the fresh vegetation in the rainforest around them.
Farming has also allowed ants to create complex societies populated with specialized workers. When a colony is new and small, a few generalized workers can perform almost every task. But as the colony grows and expands to millions of workers, an elaborate division of labor based on age and size comes into play. In a role reversal of how things work with humans, the youngest workers do the safest jobs in the colony while the oldest workers fight the wars.
But ants, like us, are engaged in a biological arms race with their enemies, working together with some bacteria to chemically attack others that could kill their fungus garden. The bacteria they employ to fight fungal parasites are the same type of bacteria that we humans use to create antibiotics. This makes leaf-cutter ants promising subjects for developing new drugs to treat infectious diseases, as well as other kinds of medical research, such as discovering new anticancer agents.
In fact, mining the rainforest for potential wonder drugs has been a longstanding pursuit of the pharmaceutical industry.
Our similarities to leaf-cutter ants break down if we look too close. Each ant has a brain made up of only a few thousand neurons, and there is no premium on personal success or individual freedom. Ants have a very high mortality rate, producing countless offspring in the hopes that a few will survive.
"The queens come out of the nest like smoke out of a volcano," says Currie. "Thousands of them. They get eaten by bats, birds and small mammals. Very few will actually survive to dig a nest."
If she lives long enough, the queen will spit out the bit of fungus she carried in her cheek, then tear off her wings to feed the fungus in her starter garden. Only 5% survive the first year in their new digs. One or two of those queens will be lucky enough to last 10 years.
The only place to see leaf-cutter ants in action locally is the Microbe Place, an interactive museum about microbiology in the UW-Madison's Microbial Sciences Building, located at 1550 Linden Drive. The building is open weekdays from 7 a.m. to 7 p.m.
