Fungus-growing ants engage in mutualistic associations with both the fungus they cultivate for food and actinobacteria (Pseudonocardia spp.) that produce selective antibiotics to defend that fungus from specialized fungal parasites. We have analyzed one such system at the molecular level and found that the bacterium associated with the ant Apterostigma dentigerum produces dentigerumycin, a cyclic depsipeptide with highly modified amino acids, to selectively inhibit the associated parasitic fungus (Escovopsis sp.).
7-S-methoxy-trifluoromethylphenylacetyl dentigerumycin ester
7-R-Methoxy-trifluoromethylphenylacetyl dentigerumycin ester
We thank the Smithsonian Tropical Research Institute for providing facilities in which to work in Panama, the Autoridad Nacional del Ambiente y el Mar for sampling and export permits, J. Heemstra and C. Walsh (Harvard Medical School) for providing synthetic piperazic acids, and A. Adams, S. Marsh, A. Pinto-Tomas and G. Suen (University of Wisconsin–Madison) for comments on a manuscript draft. This work was supported by funding from the Lundbeck and Carlsberg Foundations to M.P., from the US National Science Foundation (MCB07020255) to C.R.C. and from the US National Institutes of Health (CA24487) to J.C.
Supplementary Figures 1–8, Supplementary Tables 1 and 2, and Supplementary Methods