ارزیابی فعالیت ضد باکتریایی تعدادی از نانوذرات سنتز شده روی باکتری Pectobacterium carotovorum در شرایط آزمایشگاه

The considerable damages of Pectobacterium carotovorum (Pc) causal agent of soft rot disease on numerous crop and ornamental plants, and also post harvest rots, farmers make to use a wide variety of chemical pesticides which cause harmful effects on human health and environment. Application of safe and eco friendly methods for controlling of plant pathogens is very important in sustainable agricultural systems. Antibacterial properties of various metallic nanoparticles, such as nano-silver and nano-copper, have been investigated on important human pathogenic bacteria and, until now, limited studies have been performed on the applicability of these materials to control plant pathogenic bacteria. The purpose of this study was evaluation of the antibacterial effect of synthesized silver and copper nanoparticles using sumac extract and chitosan with a degree of solubility of more than 75%, and combination of nanosilver-chitosan and nanocopper-chitosan on Pc in laboratory conditions with the minimum inhibitory concentration method. In this research, silver and copper nanoparticles with the average size of 35 nm and spherical shape were synthesized. In the minimum inhibitory concentration assay was found that the MIC of synthesized silver and copper nanoparticles and chitosan were at concentrations of 5 ppm, 6 ppm and 0.8 ppm respectively. The MICs of nano silver -chitosan and nano copper-chitosan compositions were at concentrations of 0.5ppm-1.1 ppm and 39.3 ppm-10 ppm. According to these results, chitosan had an inhibitory effect at lower concentration than other nanoparticles. Also, the combination of silver nanoparticles with chitosan increased the antibacterial activity of silver nanoparticles. The use of nanoparticles is a cost-effective method to control plant pathogenic bacteria due to their unique physical, chemical and biological properties.