LANL: Fungus could be key to cheaper ethanol production

Sue Vorenberg | The New Mexican

5/4/2008 - 5/5/08

Fungus has sort of grown on Diego Martinez over the years.

Not literally, of course.

But the more the Los Alamos National Laboratory scientist learns about fungus, the more fascinated he becomes with it , and with finding new uses for it, he said.

While looking at the genetic code in one kind of fungus — the cryptically named Trichoderma reesei — Martinez recently found something that could help wean the nation off its dependence on foreign oil, he said.

He discovered a sequence of genes that could be tweaked to make the creature produce an enzyme much more quickly than it has in the past.

And that enzyme is a key component in the process that can turn corn husks, grass and even some municipal waste into ethanol, a more carbon-neutral fuel source, the Santa Fe native said.

"Fungus are the coolest creatures ever," Martinez said. "They're very important. Some kill other fungi and are very important in agriculture, some kill off billions of dollars worth of crops every year. They're a key component in carbon sequestration, and they're used to get citric acid and to make cholesterol drugs."

Companies will have to figure out exactly how to genetically modify the fungus to create a new species that can make the ethanol-producing enzyme in large quantities, but the data so far looks very promising, said Joel Cherry, director of research activities for Novozymes, which collaborated with Martinez and other Los Alamos National Laboratories scientists studying the fungus.

"The sequencing of the Trichoderma reesei genome is a major step toward using renewable feedstocks for the production of fuels and chemicals," Cherry said in a news release.

The fungus is best known for eating the uniforms and tents of World War II soldiers, although it has also been used in industry for several decades.

Until recently, however, its genome hadn't been mapped, which is what LANL scientists did at the lab's Joint Genome Institute.

The institute was asked by the Department of Energy to look for ways to make ethanol less expensive, Martinez said.

"The problem was the cost of the enzyme was just too expensive," Martinez said. "Those enzymes were about $5 a gallon before this project. We think after this project they could drop to as little as 30 cents a gallon."

Another benefit of the specific enzyme produced by Trichoderma reesei is that it's especially good at breaking down difficult materials — like corn stalks and husks. And that means the cost of corn for food, which has been increasing lately because of ethanol production, could drop back down, Martinez said.

"There's been a lot of discussion about the rising costs of corn, because it can't be used for human food and ethanol at the same time," Martinez said. "And if we can do this, then we can use the corn kernel for human food and the inedible stock for car food."

Oddly enough, the fungus produces a much smaller variety of plant-degrading enzymes than any other known fungus. But the ones it produces are highly effective, Martinez said.

"That's part of the puzzle — a large portion of these biomass-degrading enzymes are in very specific clusters on the genome," Martinez said. "And the fungus can secrete more protein than any other known organism, but nobody knows why."

Eventually, if the enzyme can drop the cost of ethanol, it could put a dent in the gas crisis, but that's not really the overall goal, Martinez said.

"That certainly is a hope, but the more important part is that we want to be energy independent," Martinez said.

And if it frees up a little more edible corn in the process, well, that would be fine by him, Martinez said.

"I love corn — and calabacitas, and corn tortillas, and enchiladas," Martinez said with a laugh. "Maybe this will start the 'free the corn' campaign."

Contact Sue Vorenberg at 986-3072 or svorenberg@sfnewmexican.com.