Researchers unearth bioenergy potential in leaf-cutter ant communities

As spring warms up Wisconsin, humans aren't the only ones tending their gardens. At the University of Wisconsin-Madison Department of Bacteriology, colonies of leaf-cutter ants cultivate thriving communities of fungi and bacteria using freshly cut plant material.

While these fungus gardens are a source of food and shelter for the ants, for researchers, they are potential models for better biofuel production. "We are interested in the whole fungus garden community, because a lot of plant biomass goes in and is converted to energy for the ants," says Frank Aylward, a bacteriology graduate student and researcher. Aylward is the lead author of a study identifying new fungal enzymes that could help break down cellulosic-or non-food-biomass for processing to fuel.

"All the enzymes that we found are similar to known enzymes, but they are completely new; no one had identified or characterized them until now, " Aylward says. Building on Aylward's previous study of these gardens, the researchers relied on genome sequencing provided by the U.S. Department of Energy Joint Genome Institute (JGI) and support from Roche Applied Science's 10 Gigabase Grant Program to understand the unique roles of fungi and bacteria. In addition to sequencing the genome of Leucoagaricus gongylophorous, the fungus cultivated by leaf-cutting ants, the researchers looked at the genomes of entire, living garden communities.

"We really tried as thoroughly as possible to characterize the biomass degrading enzymes produced," Aylward says. "Identifying all these new enzymes really opens the door to technological applications, because we could potentially mix and match them with others that we already know about to achieve even better biomass degradation."