Biosynthesis and characterization of copper nanoparticles constructed by fungi isolated from several industrial centers in Isfahan

Cleanliness, high adaptability to the environmental conditions and easily manufacturing leaded to attention to the use of microorganisms, including fungi in nanoparticles production. The aim of this study was biosynthesis of copper nanoparticles by fungi isolated from soil and industrial wastewaters and characterization of the synthesized nanoparticles. Sampling was carried out from the soil and waste water of several coppersmiths and plating plants in Isfahan, Iran. After analysis of chemical and biological parameters of samples, Czapek Dox medium containing CuSO4 was used for isolation of fungi. Minimum inhibitory concentration of copper ions on the selected fungi was assessed by agar diffusion method. The most resistant fungi were identified based on morphology and molecular detection. In the second step, the characteristics of copper nonoparticles produced by the selected fungi were analyzed by X-ray diffraction (XRD), UV-visible spectroscopy and transmission electron microscopy (TEM). Among the Cu-resistant fungi, Fusarium solani CBS490.63 and Paecilomyces variotii BAB-1547 possessed the highest resistance to copper with MIC of 4.5 mM and 4 mM, respectively. The results of UV-visible spectroscopy showed an absorption peak after applying 800c heating in the wavelength of 400 nm. X-ray diffraction and TEM results showed that the copper nanoparticles were in the form of hexahedron with the diameter of 17-29 nm. The isolated fungi were efficient for biological synthesis of copper nanoparticles that according to XRD and TEM results had the single-phase formation and purification characteristics similar to nanoparticles reported in other studies with minimal environmental contamination and less toxicity.