Extracellular Synthesis of Silver Nanoparticles by Aspergillus terreus: Biosynthesis, Characterization and Biological Activity

The development of fast, cost-effective, and “eco-friendly” method for the production of silver nanoparticles is an important aspect of nanotechnology today. In this paper, ten fungal strains isolated from marine sediment in Mediterranean Sea (Alexanderia) were screened for their abilities to synthesis silver nanoparticles. Aspergillus terreus MALEX was selected as the most active strain. The silver nanoparticles were characterized by UV–vis spectrophotometry, X-ray diffraction analysis, and Scanning electron microscopy (SEM). UV–visible spectrum of the aqueous medium containing silver ion showed a peak at 420 nm corresponding to the plasmon absorbance of silver nanoparticles. SEM studies showed formation of well-dispersed nanoparticles in the range of 15–29 nm and the shape of nanoparticles was spherical. The biosynthesized silver nanoparticles exhibited high activities against four pathogenic bacterial strains (Staphylococcus aureus, Klebsiella pneumoniae, E. coli, and Salmonella sp.), four mycotoxigenic fungal strains (Fusarium solani, Alternaria alternata, Aspergillus flavus, A. ochraceus).