Green Synthesis of Copper Nanoparticles Extracted From Guar Seedling Under Cu Heavy-Metal Stress By Trichoderma Harzianum And Their Bio-Efficacy Evaluation Against Staphylococcus Aureus And Escherichia Coli

Copper nanoparticles were successfully synthesized with the help of the agriculturally beneficial fungus Trichoderma harzianum through a simple green and eco-friendly route. The objectives of this study were to: 1) evaluate the application of Trichoderma harzianum and assess the effect of guar plant cultivation on heavy metal contaminated lands of copper in municipal and industrial wastewaters, and 2) develop a method to increase the antibacterial effects on the risk of two bacteria (Staphylococcus aureus and Escherichia coli). Two factors were investigated: 1) two copper (Cu) levels, Natural Hoagland Arnold solution as a control, and application of 100 μlit Cu in Hoagland Arnold solution, and 2) two bio-fertilizer levels, no application as a control, and fungus application. Biosynthesized nanoparticles were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-Ray Diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) analysis. Diffusion disk, minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC) were used for the antibacterial tests. The results of TEM and SEM showed that the copper nanoparticles synthesize from guar extract, had a spherical structure, and a size of approximately 20 nm. The crystal structure from the XRD analysis, confirmed the synthesized particles as copper nanoparticles. The formation of Cu-NPs was confirmed by the FTIR analysis. Furthermore, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of copper nanoparticles towards bacterial growth were evaluated. The copper nanoparticles and Trichoderma harzianum fungi presented antibacterial activity against Gram positive and Gram negative bacteria. The results suggested that green synthesis of nanoparticles using guar extracts can increase their antibacterial effect. The effect of copper nanoparticles and Trichoderma harzianum fungi on biochemical properties of guar was also investigated. The results showed that the highest antioxidant enzymatic activity and proline amino acid were obtained at 100 μlit Cu and T. harzianum fungi application. Moreover, the results suggested that the use of T. harzianum fungi can be useful in increasing the resistance to heavy metal stress in plants by increasing the activity of some antioxidant enzymes and secondary metabolites.