Biosynthesis of silver nanoparticles using Salmonella typhirium

The use of microorganisms in the synthesis of nanoparticles emerges as an eco-friendly and exciting approach. In the present investigation, we report the biosynthesis of silver nanoparticles employing the bacterium Salmonella typhirium. Silver nanoparticles were synthesized through the reduction of aqueous Ag+ ion using the growth culture supernatants in the bright conditions. The synthetic process was fast, and silver nanoparticles were formed within 4 min of silver ion coming in contact with the cell filtrate. An absorption peak at 427 nm in a Uv-vis spectrophotometer was detected indicating the presence of Ag nanoparticles. The morphology of nanoparticles was observed by transmission electron microscopy. The size of the nanoparticles was determined to be 87 +/- 30 nm, applying dynamic light scattering. Reduction degree of Ag+ was measured as 75% by atomic absorption spectrophotometry. The silver nanoparticles have been prepared from silver sulfate during this investigation for the first time.