Dung-inhabiting fungi: a potential reservoir of novel secondary metabolites for the control of plant pathogens

Coprophilous fungi are a large group of saprotrophic fungi, mostly found in herbivore dung. The number of these fungi are investigated is continuously increasing and new species and genera continue to be described. Dung-inhabiting fungi play an important ecological role in decomposing and recycling nutrients from animal dung. They produce a large array of bioactive secondary metabolites and have a potent enzymatic arsenal able to utilize even complex molecules. Bioactive secondary metabolites are actively involved in the interaction with and defence against other organisms whose growth can be inhibited, resulting in an enhanced ecological fitness of producer strains. Currently these antibiotics and bioactive secondary metabolites are of interest especially in medicine, while very little information is available concerning their potential use in agriculture. This review introduces the ecology of dung-inhabiting fungi with particular emphasis on the production of antibiotic compounds as a mean to compete with other microorganisms. Due to the fast pace of technological progress, new approaches are proposed in order to predict the biosynthesis of bioactive metabolites. Coprophilous fungi should be considered as elite candidate organisms for the discovery of novel antifungal compounds, above all in view of their exploitation for crop protection.