Influence of biosynthesized silver nanoparticles on keratinase activity and mycelial growth of dermatophytes

Abstract

Objective Among different nanomaterials, silver nanoparticles (SNPs) exhibited high antifungal potency compared with other types of nanoparticles (NPs), and this property is often very helpful, particularly against fungi resistant to conventional antifungal agents. However, synthesis of SNPs can generate toxic waste during the preparation process. Accordingly, new technique using non-toxic routes have been researched for the synthesis of SNPs using cell-free filtrate of Aspergillus niger and evaluate their effect against some dermatophytes spp.
Methods The proposal of our study was to biosynthesize SNPs using cell-free filtrate of Aspergillus niger as reducing agent. The characterization of biosynthesized SNPs was carried out by UV-Visible spectroscopy, Fourier transform infrared spectroscopic analysis (FTIR) and scanning electron microscopy (SEM). The antifungal effect of the NPs against dermatophytes was also evaluated. The minimum inhibitory concentration (MIC) was determined by broth microdilution method.
Results Spherical NPs 15–50 nm in size were obtained. The biosynthesized SNPs exerted pronounced morphological alteration in the fungal mycelia. Additionally, the inhibition of keratinase activity of the tested dermatophytes was also recorded.
Conclusion The results indicate that SNPs can be synthesized in ecofriendly, inexpensive and promising technique by fungal strain of A. niger, and it has considerable antifungal activity in comparison with other antifungal drugs.