Soil Fungi as Biomediator in Silver Nanoparticles Formation and Antimicrobial Efficacy.

INTRODUCTION AND OBJECTIVES

Biogenic agents in nanoparticles fabrication are gaining great interest due to their lower possible negative environmental impacts. The present study aimed to isolate fungal strains from deserts in Saudi Arabia and assess their ability in silver nanoparticles (AgNPs) fabrication and evaluate their antibacterial effect.

METHODS

Soil fungi were identified using 18s rDNA, and their ability in NPs fabrication was assessed as extracellular synthesis, then UV-vis spectroscopy, dynamic light scattering (DLS), energy-dispersive X-ray spectroscopy, and transmission electron microscopy were used for AgNPs characterization. The antibacterial activity of fungal-based NPs was assessed against one Gram-positive methicillin-resistant (MRSA) and three Gram-negative bacteria (, , and ). Ultrastructural changes caused by fungal-based NPs on were investigated using TEM along with SDS-PAGE for protein profile patterns.

RESULTS

The three fungal isolates were identified as sp. (MN995524), (MN995493), and sp. (MN995550), and their filtrate reduced Ag ions into spherical P-AgNPs, G-AgNPs, and C-AgNPs, respectively. DLS data showed an average size between 12.26 and 70.24 nm, where EDX spectrums represent Ag at 3.0 keV peak. G-AgNPs displayed strong antibacterial activities against , and the ultrastructural changes caused by NPs were noted. Additionally, SDS-PAGE analysis of treated revealed fewer bands compared to control, which could be related to protein degradation.

CONCLUSION

Present findings have consequently developed an eco-friendly approach in NPs formation by environmentally isolated fungal strains to yield NPs as antibacterial agents.