Scientists at the Peoria Ag Lab are concocting a new solution to a problem that's long plagued the ethanol production process.
Baker's yeast converts the glucose sugars it eats into ethanol. But bacteria competes with yeast, and can diminish the production of the biofuel by upwards of 40 percent. At the biggest plants, the losses can mount into the millions of dollars when plants are forced to shut down for decontamination.
Shao Lu is a research microbiologist with the USDA's Agricultural Research Service in Peoria. He says most ethanol producers use antibiotics to fight back, but that's a problem with increasing antibiotic resistance.
That's why Lu and his colleagues are testing a genetically-modified baker's yeast that produces endolysin. He says the compound works like the video game character Pac-Man, chewing through bacterial walls.
Like a virus, endolysin then tricks the bacteria into helping it reproduce.
"It is very effective. We show in a lab scale at least 85% decrease in bacteria contamination compared to a contamination control," he said. "We were also able to reduce acetic acid, and also lactic acid, from 40% to 70% decrease."
Ethanol production increased by up to 40 percent in the trials. Lu says the next step is finding industry partners and testing the method on a commercial scale.
"[We] ultimately would like to convince the industry from not using as much antibiotics as possible, as we know that resistance can develop very quickly," Lu said. "And it's also for the more cost effective way, more sustainable, to use our technology than just to add antibiotics to their adoption."
The U.S. Energy Information Administration says the nation has an annual ethanol production capacity of more than 17 billion gallons.
