Research centered around a small, fast-growing type of grass may be leading the way to a more efficient and high-yield source of energy.
In a report published Oct. 10 in the Proceedings of the National Academy of Sciences, U. California-Berkeley research geneticist George Chuck, a geneticist at the U.S. Department of Agriculture’s Plant Gene Expression Center, and his team genetically modified switchgrass so that it produces increased amounts of starch — the product which is eventually broken down into biofuel.
By introducing a gene — corngrass1 — from corn into switchgrass, Chuck and his team created a plant that never develops past a juvenile state and yields more than twice the amount of starch produced by unmodified switchgrass. These traits make the modified plant easier and less costly to break down into fuel because it contains less of the organic polymer lignin, which strengthens cell walls.
While Chuck said that the finding, a result of approximately six years of experimentation, will not be applicable to biofuel production anytime soon, the research could be a step toward addressing energy issues.
“We’re looking for a lot of alternatives to corn, and right now people are talking about alternatives like switchgrass,” said Chuck. “I think there’s going to be lots of different answers to the whole energy crisis, and this will definitely be a part of it. We could potentially solve our transportation energy problems just by growing crops like switchgrass.”
Chuck added that switchgrass has come to be seen as a viable alternative to fossil fuels and corn as a source of energy because it has a much higher net energy gain than corn and uses a marginal amount of crop land.
Greg Hartgraves, senior director of research for Poet LLC, the largest corn-based ethanol producer in the United States, said that the company has begun to consider crops other than corn, including switchgrass.
“Humans have made alcohol from cellulose for thousands of years, but the challenge we face is making it economically viable in large quantities for fuel,” Hartgraves said. “Anything that can increase carbohydrate content per unit of weight of biomass can have a significant impact on the economics.”
The company has begun construction on a processing facility in Iowa, scheduled to open in 2013, which will produce ethanol from sources such as corn biomass but may also work toward using switchgrass.
Although many companies and scientists say that biofuels are increasingly becoming an inevitable alternative to fossil fuels, the idea has met with criticism from other scientists.
Tadeusz Patzek, professor of petroleum and geosystems engineering at the University of Texas at Austin, said that the modified switchgrass may be more dangerous than helpful.
“Older plants need lignin for structural stiffness,” Patzek said. “So the ‘always young’ plants, which are also huge, will lay on the ground, be stunted in growth and die … If these modified switchgrass genes were to spread to wild grasses, the impact would be catastrophic.”
However, Chuck said that the fact that the plants are fixed in a juvenile phase of development means that they never flower and thus never spread their seed.
Chuck added that using native grass like switchgrass is not new and could actually help the land it grows on.
“Native grasses such as switchgrass … actually help preserve, or even improve cropland, compared to growing corn which causes loss of top soil and nitrogen runoff,” Chuck said in an email.