Mycogenic Silver Nanoparticles: Promising Antimicrobials with Fungistatic Properties

The antimicrobial activity of silver nanoparticles (AgNPs) makes them a valuable tool in various industries. Recently, biosynthesis has become the preferred method for nanoparticle synthesis, and among organisms that can be used as AgNP producers, filamentous fungi have attracted the greatest interest. In particular, wood decay fungi are considered promising candidates for AgNP biosynthesis. Biogenic AgNPs have been proven to have strong antibacterial potential and antifungal activity. The aim of this study was to evaluate the antifungal potential of AgNPs synthesized using the brown-rot decay fungus Gloeophyllum striatum DSM 9592 against four pathogenic fungal strains: Candida albicans, Malassezia furfur, Aspergillus flavus and Aspergillus fumigatus. Moreover, changes in the tested strains' lipidome and cell membrane properties induced by the presence of AgNPs were investigated. The results revealed that the obtained AgNPs exerted fungistatic activity against all the strains tested. M. furfur, with a MIC value of 0.39 μg/mL obtained for all AgNP types, was found to be the most susceptible to the action of AgNPs. The lipidomic analysis revealed that the presence of AgNPs caused an increase in cell membrane fluidity in both A. flavus and C. albicans, and the mechanisms of response to AgNPs differed between the tested strains.