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Researchers in Wisconsin think ants may help commercialize cellulosic ethanol.

In an article published in Ethanol Producer Magazine [4], Craig Johnson writes that at the Great Lakes Bioenergy Research Center [5](GLBRC) in Madison, Wis., researchers are looking to leafcutter ants for new enzymatic processes that will further progress efforts to commercialize cellulosic ethanol.

According to Johnson, leafcutter ants [6], which are found in tropical climates and live in enormous colonies that can number in the millions, have evolved several features over time that make their particular cocktail of enzymes attractive to researchers.

In his piece titled “Ants May Provide Cellulosic Solution“ [7], Johnson quotes Garret Suen, a post doctoral research fellow at GLBRC.

“Our lab is an evolution and ecology lab, and we’re very interested in natural systems that take advantage of lignocellulolytic biomass and use microbes to break down cellulosic feedstocks,” Suen told Johnson. “If we go to a system that is specialized to produce exactly what it is we’re looking for, we may find something of use.”

Converting plant cell walls into simple sugars, the basic premise for cellulosic ethanol, is a major challenge for scientists. Leafcutter ants, which tend massive fungal gardens of their decaying byproducts, may present a worthwhile solution.

Before receiving a U.S. Department of Energy (DOE) grant, the GLBRC was already studying the symbiotic relationship between the ants and their fungal gardens. Over 50 million years, the ants and the fungus have evolved to the degree that if the ants were to die, or are removed from the system, the fungus dies as well, and vice versa.

“The fungus-growing ant system is obligate, and one of the most complex symbioses that’s described in nature,” Suen said.

Garret Suen [8] brings a distinguished background to this research. Previous research includes understanding prokaryotic diversity in the post genomics era and modeling and simulating army ant raids. He received his Ph.D. in Biology from Syracuse University and his Master of Computer Sciences degree from the University of Calgary. He also received two Bachelor of Science degrees from the University of Calgary in Computer Sciences and Biological Sciences.

Currently serving as the Reviewer for the Fungi and Algae Proposal Study Panel of the DOE Joint Genome Institute's Community Sequencing Program [9], Suen has received several awards, one of which was first prize for the best life sciences talk at the first annual AGEP Academic Excellence Symposium at Syracuse in 2007.

Johnson states that traditional corn processing in an ethanol plant involves pre-treating with acid, steam, or ammonia to break down the bonds of lignin, hemicellulose and cellulose. After that, a cellulase is added to catalyze the cellulolysis of cellulose. Researchers at the GLBRC are studying multiple enzymes used by the ants in the fungal gardens to craft the perfect cocktail for ethanol production.

That cocktail, Suen admits, is probably a mixture of about six or seven enzymes. Using several different enzymes may allow existing ethanol plants to become multi-feedstock facilities--if they can capture the enzymes they need. One difficulty with enzymatic research is that bacteria are exceedingly difficult to grow in a lab.

“Right now we can only cultivate about one percent of bacteria in the lab,” Suen said. “The bacteria that are more difficult to cultivate are typically less aggressive bugs in the growing media and are pushed out by stronger bacteria before they can get a foothold.”

Suen said research at the GLBRC is providing a new look at some very old progress made in the ants’ natural communities. For example, with the leafcutter ants, the mixture of enzymes works in balance, but that nuanced formula would be nearly impossible to synthesize in a lab. “There is a renaissance, and researchers are going back to natural communities, an area called natural products. These are novel compounds in that no one has ever seen them before,” Suen said.

The Great Lakes Bioenergy Research Center is one of three DOE Bioenergy Research Centers funded to make transformational breakthroughs that will form the foundation of new cellulosic biofuels technology.

Image courtesy of Flickr [10]