بررسی اثر نانوذرات نیترات نقره سنتز شده با استفاده از عصاره‌ گیاه زنیان بر رشد باکتری Xanthomonas arboricola pv.juglandis

In recent years, nanotechnology has gained a noticeable rise and is used in drug delivery system, increasing the speed and sensitivity of recognition of diseases and providing better treatment methods. Among various methods have been proposed for the synthesis of nanoparticles, biosynthesis using plants extrac is highly accepted due to simplicity, low cost and as well as high safty. This study aimed to evaluate the antibacterial effect of silver nanoparticles (AgNPs) against Xanthomonas arboricola pv.juglandis. This bacterium was isolated from walnut gardens of lorestan province and identified based on biochemical and pathogenicity tests.The nanoparticles were synthesized through a slow addition 10 ml of aqueous extract of trachyspermum plant to 90 ml of silver salt 1mM solution. The structure and physical properties of nanoparticles were investigated by scanning electron microscope, spectrophotometery and X-ray diffraction. Antibacterial activity of biosynthesized nanoparticles was evaluated by disk diffusion method. Minimum inhibitory (MIC) and bactericidal concentration (MBC) were determined by microdilution method. The results showed that AgNPs had semi-spherical to polyhedral shape in a uniform distribution with the size of 13-27 nm and average size about 16 nm. Statistical analysis and mean comparison showed that there was a significant difference between the aqueous extract, silver nanoparticles and different concentrations (P< 0.05). Minimum inhibitory concentrations of plant extracs and AgNPs were 5 mg/ml, and 300 µg/ml respectively. The trachyspermum aqueous extrac and synthesized AgNPs with it created an inhibitory halo with a diameter of 8 and 11 mm respectively. Based on the results of this study, application of silver nanoparticles synthesized by aqueous extract of trachyspermum plant was promising due to antimicrobial effect and can be a good alternative to bactericidal compounds (such as antibiotics) if its effectiveness is also proven in field conditions