As members of the new multimillion-dollar center aimed at developing sustainable biofuels and bioproducts, two Nebraska plant scientists plan to spend the next five years working to expand the oil-producing capability of sorghum.

In July, U.S. Energy Secretary Rick Perry announced that $104 million in Department of Energy funds would be awarded to establish the Center for Advanced Bioenergy and Bioproducts Innovation (CABBI), located at University of Illinois at Urbana-Champaign. The University of Nebraska-Lincoln is one of 15 institutions partnering with the University of Illinois in the center's efforts.

UNL biochemistry professor Edgar Cahoon and agronomy and horticulture professor Tom Clemente, members of the university's Center for Plant Science Innovation, will lead Nebraska's efforts in the project. The DOE funds will be used to address the goal of genetically enhancing sweet sorghum and biomass sorghum to enable stems and leaves to synthesize vegetable oil in these tissues.

Crop for marginal lands
One advantage of oil-producing sorghum, Clemente says, is that sorghum is a sturdy, drought-tolerant crop that can be grown on more marginal lands with fewer inputs — and won't displace corn or soybean acres.

"There's a lot of land available, and you can still add value to create jobs and industry, not only in Nebraska but across the U.S.," Clemente says. "The idea is we can create a coproduct in sorghum that makes it more valuable on a per acre basis. We can get more biomass per acre with sweet and biomass sorghum, and we can turn vegetative tissue into oil-producing factories. If you can get anything greater than 5% oil accumulation in the stalk, we can contribute to added value at the farm gate."

However, Clemente notes, the industry and demand for sorghum-based oil products must first come together, and processing plants are needed to handle and purchase the material from growers.

The Illinois-based Center for Advanced Bioenergy and Bioproducts Innovation will focus on developing high-tech feedstocks that can synthesize the starting materials that can then be isolated and used for the production of high-value molecules for bioproducts and biofuels. Also, new biologically based conversion systems can be adapted to cost-effectively produce end-use products like biodiesel, organic acids, jet fuels and other high-value molecules. Importantly, a sustainability framework is a critical assessment metric of the program. This metric will addresses all three prongs of sustainability: environment, social and economic.

Clemente and Cahoon, along with other researchers, are investigating whether sorghum's novel chemistry and lignin content could produce high-value molecules that could replace petroleum-based materials.

"If the oil has the right composition, you can use any vegetable oil as starting material to synthesize into jet fuel," says Clemente. "Once you have this material from any renewable feedstock, there are all sorts of things you can make with it. That's the beauty of using oil vs. starch."

Other researchers have been able to produce oil in tobacco leaves, a broadleaf plant, but more work is needed to transfer the trait to a grass like sorghum, Clemente says.

Other center partners, including the Brookhaven National Laboratory in N.Y., Iowa State University, the University of Illinois and the HudsonAlpha Institute for Biotechnology in Huntsville, Ala., are also exploring whether sorghum can be modified to produce more oil.

"These kinds of taxpayer investments in public sector research allow us to take the time to develop and hand off these technologies to the private sector so they can create industry," Clemente says. "It's not the public sector that will create it. Our goal is the foundational innovations that can be taken to and created on the marketplace."