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Fueling the future with sorghum

Wilfred Vermerris is looking for alternatives in fossil fuels in sorghum. 

“Sorghum is a very tough species, and it’s very adaptable,” said Vermerris, associate professor in microbiology and cell science, and Genetics Institute faculty member. “In its original state, it doesn’t need all that much to begin with. It’s quite efficient with its water use.”

Sorghum has a tall, green, leafy stalk that looks similar to corn. Except, instead of a slender, yellow tassel at the top, it has a seed-bearing panicle. Sorghum originated in Africa, where it was domesticated to be eaten as a grain.

Not too long ago, researchers realized sorghum could be used to create biofuel. By squeezing the sugar-rich juice from a stalk of a particular type of sorghum, (“sweet” sorghum) and adding microbes (such as yeast) to ferment the sugars into alcohol. the process can produce butanol.

But why the need to find an alternative to ethanol?

Ethanol can be corrosive, particularly in car engines made before 2001, as well as most boats and lawnmowers Butanol is less corrosive than ethanol, has a higher energy density than ethanol, and also mixes better with gasoline. However, it’s harder to make.

There is also some concern that continued reliance on corn as a source for biofuel will place a strain on American agriculture’s capacity to provide enough corn for both food and fuel.

Sorghum is not grown as a food crop in the U.S. It is harvested for animal feed, or to be used as an ingredient to make biodegradable plastic.

Vermerris’ goal is to improve the ways sorghum can be used as a renewable substitute in lieu of nonrenewable fuels, such as petroleum, and will remain a viable alternative in light of the changing climate.

One of the anticipated side effects will be changes in rainfall– when it will rain and how much.

“We’re working on sorghums that are less thirsty,” Vermerris said. “That can produce good yields with relatively limited water inputs. And, on top of that, can survive periods of drought.”

While many other plants typically become stressed, or die, during dry periods sorghum does not. It goes into a sort of hibernation, keeping itself alive from its stores of moisture, until the rain returns, and it can put its energy toward growing.

It has also demonstrated its ability to thrive in hot climates, which all models indicate will only escalate in the South going forward.