Mycosynthesis of Copper Nanoparticles by Aspergillus spp. Isolated from the Tomato Rhizosphere and Evaluating their Inhibition Efficacy on the Pathogenic Fungus Fusarium oxysporum

Abstract

Five Aspergillus isolates were isolated from the tomato rhizosphere were tested for their activity for mycosynthesis of copper nanoparticles. Aspergillus spp. in addition of the pathogenic fungus Fusarium oxysporum were identified based on morphological and molecular methods by ITS sequences. Fungal isolates were identified as Aspergillus niger isolate Abier-4, Aspergillus oryzae isolate Abier-5, Aspergillus fumigatus isolate Abier-2, Aspergillus nidulans isolate Abier-3 and Aspergillus carbonarius isolate Abier-1, as well as the plant pathogenic fungus F. oxysporum isolate Abier-6, these fungi were registered in the Global Gene Bank at the NCBI site with the accession numbers ON624353.1, ON624352.1, ON624350.1, ON624351.1, ON624347.1, and ON624357.1, respectively. The mycosynthesis of copper nanoparticles was comfort by heterochromia which turn from blue to brown and a light yellowish brown color. In spectroscopy the highest peaks of absorbance were at the wavelength 250-350 nm. The dimensions of these particles, which were in the range of 14.318 - 93.408 nm using scanning electron microscope. The results of the inhibition effects of F. oxysporum growth by the copper nanoparticles showed the inhibition effects for all treatments of copper nanoparticles synthesized by all studied Aspergillus species, the highest inhibition of the synthesized copper nanoparticles was obtained from the copper oxide solution treated with the hot and cold biomass extract of the fungus A. carbonarius, as the inhibition zones reached 3 and 2.9 cm, respectively.