New Antifungal Compound From Ant Farms

Attine ants are farmers, and they grow fungus as food. Pseudonocardia and Streptomyces bacteria are their farmhands, producing metabolites that protect the crop from pathogens. Surprisingly, these metabolites lack common structural features across bacteria from different geographic locations, even though the ants share a common ancestor. Now, researchers report in ACS Central Science they have identified the first shared antifungal compound among many of these bacteria across Brazil. The compound could someday have medical applications.

Attine ants originated as one species at a single location in the Amazon 50 million years ago. They have evolved to 200 species that have spread their farming practices throughout South and Central America. In exchange for food, bacteria at these farms produce small molecules that hold pathogenic fungi such as Escovopsis in check. However, these molecules differ from region to region, suggesting a highly fragmented and geographically limited evolutionary history for the bacteria. Monica T. Pupo, Jon Clardy and colleagues wanted to find out if any antifungal bacterial metabolites with broader distribution had been overlooked in prior investigations.

In a study of bacteria from ant nests at multiple sites in Brazil, the team discovered that nearly two thirds of Pseudonocardia strains produced a potent antifungal agent, which they called attinimicin.