Evaluation of inhibitory mechanism of Ag colloidal nanoparticles against pathogenic microorganisms of Pseudomonas syringae and E.coli

The emergence of nanoscience and nanotechnology in last decade presents opportunities for exploring theantibacterial effect of metal nanoparticles .The use of metal nanoparticles to combat bacterial infections is one of themost widespread applications of nanotechnology in the field of antibacterial. In this study, antibacterial effect ofzerovalent Ag nanoparticles on E.coli and Pseudomonas syringae were studied for inhibition of bacterial cell growth. Atfirst Ag nanoparticles were synthesized using an easy and simple method by reducing and stabilizing the sodium citratein aqueous environment. Then different concentrations of Ag nanoparticles containing, 0, 5, 10, 15, 20 and 25 μM onbacteria P. syringae and 0, 6, 7, 8, 9 and 10 μM on bacteria E.coli (DH5α) were added to grown bacteria on nutrient agarmedium . Minimum inhibitory concentration (MIC) of silver nanoparticles for P. syringae and DH5α were determined.Maximum inhibitory percent for P.syringae and E.coli were 99% and 98%, respectively. Scanning electron microscopy(SEM) was used to produces image of nanoparticle size. Results suggested that the bactericidal effect of metalnanoparticles has been attributed to their small size and Ag-NPs could be used as an effective antibacterial material.

Keywords:

Antibacterial , Metal nanoparticles , MIC , SEM