Isolation and characterisation of novel antimycotics

Amazonian leaf-cutter ants began farming fungus as a food source for their offspring and queen between 50-60 million years ago. They grow the fungus on the leaves they have collected and they also grow a bacterium wit the fungus which produces chemicals to inhibit the growth of any other fungi or bacteria. This clever symbiotic relationship has evolved over tens of millions of years and the bacteria are repaid by being fed by secretions from specialised glands on the ant bodies. The chemicals produced by the bacteria have not been identified and so during this project we will isolate and identify the compounds and investigate whether these compounds could be used as drugs for treatiing human and animal infections.

Attine ants, better known as leaf-cutter ants, grow fungus on masticated leaves as a sole food source for their larvae and queen. The fungus (cultivar) is passed vertically from generation to generation along with a symbiotic bacteria belonging to the order Actinomycetes. This symbiont is co-inoculated onto the leaves along with the fungal cultivar and produces antifungal compounds (antimycotics) which prevent contamination of the fungal garden. The aims of this proposal are to isolate the Actinomycete symbionts from different genera of Attine ants, identify the antimycotics and clone the biosynthetic genes. We anticipate that this novel source of antimycotics may have uses in human and animal medicine and this project will lay the groundwork for the genetic and chemical engineering of these compounds for clinical use.