Abstract
The present study determined if metal ions (zinc sulphate, silver nitrate, copper sulphate, manganese sulphate and ferric chloride) can be used as precursors to prepare nanoparticles using a baker’s yeast culture medium. The particles were characterized using Fourier transform infrared (FTIR), scanning electron microscope‒energy-dispersive X-ray (SEM-EDX), transmission electron microscopy (TEM), and X-ray powder diffraction (XRD). The antibacterial activity against Escherichia coli and Streptococcus aureus was also evaluated. Saccharomyces cerevisiae strain A12 culture only synthesized nanoparticles using a silver nitrate solution. FTIR indicated that the protein might play a role in capping the nanoparticles, which formed large aggregates and contained silver, oxygen and a small amount of phosphorus. The nanoparticles were spherical, ranging in size from 9 to 85 nm, crystalline and characterized as Ag2O, however, they demonstrated weak antibacterial activity.