Biological Activity of Gold Nanoparticles towards Filamentous Pathogenic Fungi

Abstract

Gold nanoparticles (GNP) were synthesized, characterized and their antifungal activities investigated against three pathogenic fungi of different genera and species ( Fusarium verticillioides , Penicillium citrinum and Aspergillus flavus ). The anti-fungi treatments efficiency of the GNP (concentrations: 0, 0.05, 0.1 and 0.2 mg L -1 in PDA media) were evaluated at 2, 4, 6 and 8 days after incubation by measuring the diameter of fungal colonies and investigating fungi structure alterations by scanning electron microscopy (SEM). It was observed that the GNP concentration increased, fungal colony growth diameter reduced. However, the highest GNP concentration applied in the experiment was not able to completely inhibit fungal growth. The SEM analysis of the fungi structure Au treated showed damaged hyphae and unusual bulges that were not observed in fungi that growth on medium without treatment (Control). Although up to the highest concentration of GNP media applied did not completely inhibited fungi growth, the hyphae modifications led growth reduction which could influence the toxins production by these fungi.