Engineer Converts Yeast Cells Into Sweet Crude Biofuel

Researchers at The University of Texas at Austin's Cockrell School of Engineering have developed a new source of renewable energy, a biofuel, from genetically engineered yeast cells and ordinary table sugar. This yeast produces oils and fats, known as lipids, that can be used in place of petroleum-derived products.

Assistant professor Hal Alper, in the Cockrell School's McKetta Department of Chemical Engineering, along with his team of students, created the new cell-based platform. Given that the yeast cells grow on sugars, Alper calls the biofuel produced by this process "a renewable version of sweet crude." The researchers' platform produces the highest concentration of oils and fats reported through fermentation, the process of culturing cells to convert sugar into products such as alcohol, gases or acids. This work was published in Nature Communications on Jan. 20.

The UT Austin research team was able to rewire yeast cells to enable up to 90 percent of the cell mass to become lipids, which can then be used to produce biodiesel.

"We took a starting yeast strain of Yarrowia lipolytica, and we've been able to convert it into a factory for oil directly from sugar," Alper said. "This work opens up a new platform for a renewable energy and chemical source."

The biofuel the researchers formulated is similar in composition to biodiesel made from soybean oil. The advantages of using the yeast cells to produce commercial-grade biodiesel are that yeast cells can be grown anywhere, do not compete with land resources and are easier to genetically alter than other sources of biofuel.