Biotechnology
Morahem Ashengroph; Somayeh Fattahi
Abstract
Introduction: Silver nanoparticles (AgNPs) are used in a variety of industries, including coatings, disinfectants, water purification, and medicine, due to their small size and unique physical and chemical properties. To avoid the use of chemicals, extracellular biosynthesis of AgNPs using fungal systems ...
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Introduction: Silver nanoparticles (AgNPs) are used in a variety of industries, including coatings, disinfectants, water purification, and medicine, due to their small size and unique physical and chemical properties. To avoid the use of chemicals, extracellular biosynthesis of AgNPs using fungal systems is an appropriate method. In this study, the extracellular biosynthesis of AgNPs by the resting cell of the fungus Aspergillus niger ZRS14 was investigated, and the synthesis process was optimized using Taguchi's statistical method. Methods: The effect of biomass parameters, incubation time, pH and silver nitrate concentration in three levels was performed using Qualitek-4 software. The characteristics of the synthesized AgNPs were determined by spectroscopic analysis including UV-Vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and field emission scanning electron microscopy (FESEM). Results and discussion: The results showed that the selected strain under optimal conditions including 2 mM silver nitrate, pH 6, temperature 32 ◦C, and after 72 h incubation, spherical silver nanoparticles with an average size of 24 to 38 nm in extracellular form synthesized under resting cell strategy. Because of the coating of fungi-secreted proteins, synthetic spherical elemental AgNPs have a crystalline nature, a small size, and high stability.
