Antimicrobial Potentials of Iron Oxide and Silver Nanoparticles Green-Synthesized in Fusarium solani

Abstract

The current study aimed to synthesize, characterize and determine the antibacterial activity of iron oxide (Fe₃O₄ NPs) and silver nanoparticles (AgNPs) green-synthesized using Fusarium solani. Fungal mass was applied to produce NPs, followed by analyzing NPs using scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. Theantimicrobial test was performed by the agar well diffusion method and the microdilution protocol (determining the minimum inhibitory concentration or MIC and the minimum bactericidal concentration or MBC) against Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa and Escherichia coli. The highest optical densities for produced AgNPs and Fe₃O₄ NPs were detected at 420 and 215 nm, with a spherical shape and size of 27.5-58.3 nm and a cubic-spherical shape and size of 55.3-84.2 nm, respectively. Ag NPs had more antibacterial activity than Fe₃O₄ NPs, but they were not significantly different in most cases. The most sensitive and resistant bacteria were S. aureus and P. aeruginosa for both NPs, with the MIC of 10 and 40 μg ml^-1 as well as the MBC of 20 and 80 μg ml^-1 for Ag NPs against S. aureus and P. aeruginosa, respectively. The results were weaker for Fe₃O₄ NPs than for Ag NPs, with the MIC of 20 μg ml^-1 for B. cereus and S. aureus, and 40 μg ml^-1 for P. aeruginosa and E. coli, with the MBC of 40 and 80 μg ml^-1, respectively. The antibacterial properties of the produced NPs indicated that these antimicrobial agents were highly reactive and prevented the growth of unwanted microorganisms.