Danforth Center looks to the future of ethanol on a hot planet

Date:10-10-2017


Some controversy surrounding ethanol as a fuel source arises from the “food vs. fuel” debate: Should arable land typically reserved for food crops be devoted instead to fuel production?

Researchers at the Donald Danforth Plant Science Center think that sorghum — though still a common food grain — could provide a better alternative than the corn-based ethanol that dominates today’s domestic supply chain.

They hail its ability to grow in hot, dry conditions, making sorghum well-suited for use on marginal land not dedicated to other crops. Besides efficient use of water, it also requires fewer fertilizer inputs, helping boost bang-for-the-buck in terms of its return on energy.

Those qualities lead some at the Creve Coeur-based plant research facility to believe sorghum “is positioned to become the premier bioenergy crop” in the country, catapulting beyond the percentage it already contributes to U.S. ethanol production.

That pitch has evidently piqued the interest of the U.S. Department of Energy, which, in a project announced last week, approved a five-year, $16 million grant for the Danforth Center, along with several partnering institutions, to research the crop’s use for bioenergy.

The efforts will focus on developing “stress-tolerant sorghum lines” by identifying genes that aid photosynthesis and water efficiency in hot environments — something project leaders say is crucial in a world warming through climate change.


“We’re going to have more heat and we’re going to have more prolonged episodes of drought,” said Tom Brutnell, the lead principal investigator for the project and the director of the Danforth Center’s Enterprise Rent-A-Car Institute for Renewable Fuels. “So it’s a safe bet to invest in a more heat-tolerant plant.”

Brutnell said the work builds on previous sorghum research done at the Danforth Center, but will place greater emphasis on the plant’s genome and applications of gene editing technology.

Ultimately, he hopes increased sorghum-based ethanol production can serve as a bridge before a broader transition toward ethanol varieties that use plant byproducts — stalks or other unused material — instead of grain or other plant parts typically consumed as food.

He says the infrastructure for widespread implementation of those lignocellulosic ethanol systems does not exist yet. But sorghum, he argues, can easily get plugged into the existing supply chain that accommodates corn ethanol in the U.S., while new research aims to develop nonedible parts of the plant into a better biofuel feedstock.

“The purpose of our research is to improve the lignocellulosic traits associated with sorghum,” Brutnell said. “Those traits that we’re going after, it’s all to build better biomass.”

Sorghum’s drought and heat tolerance has made it an increasingly popular focus of research at the Danforth Center in recent years. In January, for instance, the center was awarded a collaborative $6.1 million Bill & Melinda Gates Foundation grant to improve varieties of the crop for use as a staple food in developing countries.

“Probably half the faculty at the Danforth now have projects related to sorghum,” said Brutnell, adding that there was essentially no activity on that front as recently as five years ago. Since 2015, though, about $16 million in grants for sorghum research have been awarded to the facility.

The latest funding is especially welcome amid the looming threat of federal budget cuts — and in an era when “climate change” are dirty words to a presidential administration that denies its existence.

“Anything that hints at climate change is targeted now, which is very unfortunate,” Brutnell says.

“We don’t mention climate change in our grants because that will kill it for some,” he adds. “It’s silly that we have to self-police for word choice.”

To maneuver around the politicization of climate science, Brutnell says that he and other colleagues seeking government funds merely state facts without overtly tying them to broader climate trends wrought by greenhouse gas emissions.

“We present the reality,” he says. “Every year we’re having bigger swings in the weather — more episodic heat waves, rain events. We present the obvious.”

With those changes happening at an unprecedented rate, he worries that traditional plant breeding methods may not be able to respond quickly enough to keep up. That’s where he hopes gene editing can provide an extra dose of acceleration.

“The reality is, the environment is changing and we need to develop our crops to accommodate that change in climate.”