GAINESVILLE --- A University of Florida chemist has borrowed a page from the Betty Crocker cookbook and found a way to use baker's yeast in making chemical products used in pharmaceuticals and food.

Jon Stewart, an assistant professor of chemistry at UF, says yeast cells similar to those used to make bread and beer can make enzymes needed in experiments that are nonexplosive, nontoxic and biodegradable. The new yeast cells, called designer yeasts, even have a pleasant bonus: They leave labs smelling like fresh-baked bread.

Enzymes act as a catalyst to make molecules, are a renewable resource and are used by all organic chemists. The enzymes chemists currently use come from inconvenient sources such as human livers and disease-causing bacteria. They also need a helper molecule, or co-factor, to perform a reaction. Also, in current reactions, chemists use a chemical reagent as a catalyst, but those reagents are toxic and explosive.

"We want to solve those practical problems and allow enzymes to be used by all chemists," said Stewart.

The designer yeast enzyme eliminates those concerns and costs about the same as current methods, he said.

The enzymes found in yeast cells are special in their ability to make one extra enzyme to act as its own co-factor, yet still remain biodegradable. Stewart said the yeast is easy to ship in dry form and can be grown in the lab. In addition, designer yeasts can be created for specific kinds of organic chemistry.

One possible use for the new yeast, he said, is creating monomers, which are the building blocks for large molecules, such as polymers or plastic.

"Everything has to be as simplified as possible. We're trying to make things people can actually use," Stewart said. He currently is researching ways to create designer yeasts for chemical reactions on an industrial scale.

The theory for creating new ways of using yeast cells in the hopes of
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Contact: Jon Stewart
jds2@chem.ufl.edu
(352) 846-0743
University of Florida
18-Jun-1998