• Plant pathogenic fungi
• Fungal metabolites
• Fimicolous fungi
• Biocontrol
• Solid State Fermentation (SSF)

Herbivores mammals dung allows the growth of a wide variety of fimicolous fungi. New molecular techniques together with the more classical morphological approach make possible the identification of new species of fimicolous fungi, whose number is steadily increasing. In order to grow on a complex ecosystem, such as herbivores dung, fimicolous fungi produce a wide variety of secondary metabolites, helping them to compete with other organisms. However, bioactive metabolites produced by fimicolous fungi, especially those with antifungal activity, have been mainly evaluated for a possible application in medical field but no information are available concerning a possible use against plant pathogenic fungi. The aim of this thesis is to investigate the possible use of these secondary metabolites in the agricultural sector, mainly against plant pathogenic fungi within a sustainable crop protection strategy. The present work has been performed on three quite recently described fimicolous isolates: Cleistothelebolus nipigonensis (DSM 26817), Neogymnomyces virgineus (MB561628), Rodentomyces reticulatus (MB516520) and on two new strains of Auxarthron spp. (10405 and 10406), these last isolated, identified and described within this work. All isolates used in this work derived from herbivorous dung.
Auxarthron spp. 10405 and 10406 have been firstly identificated by morphological and molecular analysis and then assigned to Auxarthron umbrinum and Auxarthron concentricum species, respectively. Further, these two isolates have been submitted to cultural studies on different substrates and at different temperatures, resulting unable to grow at 37°C, then excluding a possible pathogenicity for humans.
Finally, these two isolates, together with the other listed before, were evaluated for their antifungal activity against some important plant pathogenic fungi, showing encouraging results. In order to obtain diffusible secondary metabolites to be evaluated for their antifungal activity, a fermentation protocol of the five fungal isolates have been setted-up. Different substrates were evaluated, in order to select one which allowed to maximize the development of the fungal biomass. Solid State Fermentation (SSF) allowed an higher biomass production, than Liquid State Fermentation and rye flour was selected as substrate.
The extraction and the purification - led by essays of antibiosis activity conducted in parallel - of metabolites from SSF substrate were carried out by Prof. Antonio Evidente from the Department of Chemical Sciences (University Federico II of Naples). From the first extraction, we obtained an aqueous phase and two organic phases (n-hexane and dichloromethane). Only organic extracts obtained from C. nipigonensis and N. virgineus showed strong antifungal activity against Alternaria brassicicola, Fusarium graminearum and Botrytis cinerea. The subsequent purification of the organic extracts resulted in the isolation of fractions and of two pure metabolites: Fusaproliferin and Terpestacin. These pure metabolites and their derivates (various compounds acetylated and methylated) were further tested against plant pathogenic fungi in order to confirm their activity. Finally, all metabolites showing antifungal activity were further used in a phytotoxicity test on tomato and cabbage plants, resulting not phytotoxic. Fimicolous fungi can be, then, considered a rich source of antifungal metabolites to be exploited both in medicine and in agriculture, this last replying to the increasing demand of an ecofriendly approach in crop protection.