Assessment the Antibacterial Properties of the Gold Nanoparticles Produced by Fusarium Oxysporum, Conjugated Streptomycin

Introduction and Aims: The development of eco-friendly methods for the synthesis of nanomaterial shape and size is an important field of nanotechnology. In the present study extracellular biosynthesis of gold nanoparticle was done by Fusarium oxysporum fungus strain and the obtained nanoparticles were conjugated with streptomycin. Finally, the anti-bacterial property of the conjugated gold nanoparticles, was studied.
Fusarium oxysporum cultured in Sabouraud Dextrose Broth (SDB) medium. Culture supernatant was subjected to chloroauric acid solution at the final concentration of 1 mmolar. Mixture was used to confirm the presence of nanoparticles with spectrophotometry methods, X-ray diffraction analysis (XRD) and Transition Electron Microscope (TEM). Conjugation of the antibiotics with gold nanoparticles was confirmed through spectrophotometry methods, TEM and infrared spectroscopy (FTIR). Minimal Inhibitory Concentration (MICs) of the mixtures evaluated by broth dilution methods and agar well diffusion plate.
Gold nanoparticles had spectral absorption peak around 530 nm wavelength. XRD results confirmed presence of the elemental gold in the mixture and TEM images have shown the nanoparticles were spherical or hexagonal and their sizes were around 25-30 nanometer. Spectrophotometry, TEM and FTIR results confirmed the conjugation process. Based on the structure of the used antibiotics and the tested bacterial strains, gold nanoparticles that were conjugated with the antibiotics had different antibacterial properties.
Biological production of gold nanoparticles by Fusarium oxysporum can be done and conjugation of gold nanoparticles with streptomycin confirmed without any additional linkers.