Biosynthesis and Antibacterial Activity of Gold Oxide Nanoparticles by Nocardia asteroids Isolated from Soil

Nanoparticle synthesis is an advanced approach in the field of modern nanotechnology. Recent studies aim to characterize gold oxide nanoparticles produced by bacteria. These studies are of great interest and signify a significant technological advancement, particularly in the context of microorganisms. In this context, Nocardia bacteria were isolated from soil and subjected to a detailed. Nocardia is isolated from the soil. Bacterial isolation was confirmed using advanced molecular techniques. Fragments of RNA 16S were amplified and sent for the following sequence following the isolation of cell-free Nocardia asteroides, they were employed in the biosynthesis of gold oxide nanoparticles (Au2O3) by reducing a gold salt solution (HAuCl4) to form nanocrystals. The formation of Au2O3 was monitored by observing color change and the UV-VIS spectrum confirmed the decrease in gold ions. The resulting nanoparticles were characterized using Scanning Electron Microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), Transmission Electronic Microscopy (TEM), Atomic Force Microscopy – (AFM), and X-ray Diffraction (XRD). Gold oxide nanoparticles (Au2O3 NPs) were synthesized using Nocardia asteroides, and SEM analysis revealed predominantly spherical particles with an average size of 19 nm. TEM results indicated that the biologically prepared of gold oxide nanoparticles in this study exhibited sizes ranging from 12 to 23 nanometres in various shapes. XRD indicates that the produced material consists of gold oxide nanoparticles. The antibacterial activity of the gold oxide nanoparticles was assessed against pathogenic bacteria, but they exhibited no inhibitory effect on the tested bacterial isolates.