Protecting our Pollinators

People and bees have a long shared history. Honeybees, natives of Europe, were carried to the United States by early settlers to provide honey and wax for candles. As agriculture spread, bees became increasingly important to farmers as pollinators, inadvertently fertilizing plants by moving pollen from male to female plant parts as they collected nectar and pollen for food. Today, more than two-thirds of the world’s crop plants—including many nuts, fruits and vegetables—depend on animal pollination, with bees carrying the bulk of that load.

It’s no surprise that beekeeping has become a big business in the farm-rich Midwest. Wisconsin is one of the top honey-producing states in the country, with more than 60,000 commercial hives. The 2012 state honey crop was valued at $8.87 million, a 31 percent increase over the previous year, likely due in part to the mild winter of 2011–2012.

But other numbers are more troubling. Nationwide, honeybee populations have dropped precipitously in the past decade even as demand for pollination-dependent crops has risen. The unexplained deaths have been attributed to colony collapse disorder (CCD), a mysterious condition in which bees abandon their hives and simply disappear, leaving behind queens, broods and untouched stores of honey and pollen. Annual overwintering losses now average around 30 percent of managed colonies, hitting 31.1 percent this past winter; a decade ago losses were around 15 percent. Native bee species are more challenging to document, but there is some evidence that they are declining as well.

Despite extensive research, CCD has not been linked to any specific trigger. Parasitic mites, fungal infections and other diseases, poor nutrition, pesticide exposure and even climate change all have been implicated, but attempts to elucidate the roles of individual factors have failed to yield conclusive or satisfying answers. Even less is known about native bees and the factors that influence their health.

Poised at the interface of ecology and economy, bees highlight the complexity of human interactions with natural systems. As reports of disappearing pollinators fill the news, researchers at CALS are investigating the many factors at play—biological, environmental, social—to figure out what is happening to our bees, the impacts of our choices as farmers and consumers, and where we can go from here.

The Inner Lives of Cows

What do biofuels look like on the Wisconsin landscape? Some might think of corn or switchgrass. But what about that herd of cows?

What you can’t see might fool you. Cows are walking natural biodigesters, says CALS bacteriology professor Garret Suen. Their rumens are filled with rich bacterial communities that break down the cellulose found in feed into nutrients usable by the animal.

“The cow is arguably one of the most efficient cellulose degraders around, and the main reason why is that we’ve domesticated them to be that way through selection,” Suen explains. “What I argue is that we didn’t just domesticate the cow, we domesticated their microbes.”

Efficiently breaking down cellulose into simpler usable materials—a key challenge in biofuel production—is a feat naturally performed primarily by microbes. “A cow couldn’t exist without its bacteria, because it has no way on its own to break down the plants that it eats,” he says.

Suen, a researcher with the Wisconsin Bioenergy Initiative, is exploring the workings of the ruminant system in the hope of harnessing its power for industrial applications. He’s focusing on three strains of bacteria in the rumen that use different strategies to degrade cellulose. Drawing upon his background in both computational biology and genomics, Suen is using next-generation sequencing to hone in on the individual genes, enzymes and other proteins used by each and how they work together.

“Understanding the different ways that nature has come up with to degrade recalcitrant plant material will be very useful,” he says.

To date, Suen’s research group has identified some sets of genes they believe are involved, including some interesting surprises that he isn’t quite ready to share. He recently received a five-year, $750,000 early career award from the U.S. Department of Energy to advance the project. Suen hopes the work could ultimately extend even beyond bioenergy.

“Understanding how the microbes are breaking down these plant biomasses doesn’t only impact biofuels. It also has implications for areas like improving digestibility of feed and nutrient yield for the cow—which could directly affect everything from milk production to feed costs to beef quality,” he says.

O Bioneers

It wasn’t exactly panning for gold, but a lesson in “bioprospecting,” as it’s called, had students scour the campus looking for something just as valuable: invisible forms of life that could one day be key in developing a sustainable alternative to oil.

“Instead of going out and looking for precious metals, we’re looking for precious microbes,” says John Greenler, director of education and outreach at the Great Lakes Bioenergy Research Center and lead instructor of the university’s first bioenergy course for freshmen, held this past fall semester.

“Out in the environment there are a lot of microorganisms that are really good at breaking down fibrous plant material,” Greenler notes—a vexing but essential step in producing biofuel.

“Before I took this class I was only a little curious with the concept of bioenergy. Now I feel involved with bioenergy research and the possibility of using it to solve many environmental, political, and economic problems.” -Michael Polkoff

“We’re hoping to figure out how those microbes do that and then utilize that process to make biofuels—essentially, capture energy for our transportation needs the same way the microbes capture energy as a source of food,” Greenler says.

“Bioenergy: Sustainability, Opportunities and Challenges” debuted as a First-Year Interest Group (FIG) program open to 20 freshmen, and it was snapped up quickly during registration. As the bioprospecting lab shows, the course was designed to have students work on real-world problems researchers face in a new and rapidly growing field.

That includes the frustrations. Student Michael Polkoff reports that the prospecting material chosen by his group—pond scum—came up negative for microbes that produce cellulose-busting enzymes.

“While the results are depressing for the work we put into this—especially going barefoot into a freezing, sludgy drainage pond—it’s part of doing scientific research,” says Polkoff. “Sometimes you get results, other times you don’t. More importantly, we learned how research is done.”

The course has galvanized Polkoff’s interest in bioenergy. “Before I took this class I was only a little curious with the concept of bioenergy,” he says. “Now I feel involved with bioenergy research and the possibility of using it to solve many environmental, political, and economic problems.”

The course is offered through a partnership between the Great Lakes Bioenergy Research Center and the Wisconsin Bioenergy Initiative. Students visit the UW campus labs of some of the nation’s foremost researchers, and one field trip took them to CALS’ Arlington Research Station to study bioenergy field plots.

The FIG program, which clusters three courses linked by a common theme—the bioenergy course was paired with introductory chemistry and environmental studies—targets low income, minority, “first in family to college students,” says Greenler. “Overall, about 30 percent of students in the FIG program are minorities.”