What’s in the Soil? A Catalyst for Success

By Lynn Thomasson

Every season, farmers protect a variety of crops, including potatoes, raspberries and celery, from insects and weeds by applying a pesticide known as Telone II or Shell D-D. Enzymes deep in the soil break down the residues from this pesticide in less than two seconds. But what if the enzyme didn’t exist?

Scientists at Carolina found that it would take 10,000 years for just half of the active ingredient in the pesticide (1,3-dichloropropene) to decompose without the enzyme. This gives the pesticide approximately same half-life as the plutonium used in nuclear power plants. Luckily, Psuedomonas pavonaceae, the bacteria with the enzyme, is the most common species of soil bacteria.

Christopher Horvat, a senior chemistry major, was part of the team of Carolina scientists who made the discovery. Horvat wrote up the research findings with the help of his mentor - Richard Wolfenden, Carolina professor of chemistry. Results were published in the Proceedings of the National Academy of Sciences, a prominent scientific journal.

By testing the pesticide residue at various temperatures and extrapolating the results to room temperature, Horvat found the pesticide half-life without the presence of the enzyme. Horvat calls the research a gradual, but complete learning experience – one that opened up more questions along the way. Now researchers are looking into some of these questions, such as where the enzyme came from.

Before deciding to do research in Wolfenden’s lab, Horvat searched through the Office of Undergraduate Research website ( http://www.unc.edu/depts/our/) and interviewed with several professors. Horvat says he worked independently on many of the daily experiments. “Most of the direction was outlined by the teachers because they knew the material best. But if I hit a snag with something, it was up to me to work through it,” he says.

When he started working in the lab, Horvat says he found the work sometimes esoteric and complex. “It took me a while just to get through a paper in a science journal.” But after becoming accustomed to working in a lab, he says research has provided insights into the field of biochemistry.

Horvat says his research at Carolina has given him “an incredible mentoring experience,” as well as “an avenue for future research.”

“It made me love science even more,” he says.

Christopher Horvat plans to become a physician and will be attending the UNC School of Medicine next year.

Learn more about research in Professor Richard Wolfenden’s lab at
http://www.chem.unc.edu/people/faculty/wolfendenrv/rvwresproj.html#

Check out more about the discovery at http://www.unc.edu/news/archives/oct05/wolfenden102105.htm

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