Extracellular Synthesis of Silver Nanoparticles by Gram-positive bacterial strain

Silver nanoparticles (SNPs), are among the most popular nanomaterials due to their unique physical andchemical properties. Synthesis of nanoparticles by physical and chemical approaches are eco-unfriendlyand expensive. Biological method provides a feasible, safe and biocompatible alternative. In this study,synthesis of silver nanoparticles is reported by Gram-positive bacterial strain. The bacteria were isolatedfrom soil samples. A gram positive bacterial strain resistant to silver nitrate was selected for the synthesisof AgNPs. The supernatant of bacterial strain was added to the reaction solution containing 1mM of silvernitrate. After the color change, reaction solution was analyzed using UV–Vis spectrophotometer. Amongthe bacterial isolates and purified from soil samples, a bacterial isolated was randomly selected for theability to form silver nanoparticles. This was confirmed by formation of brown colour and the visualobservation and UV–Vis absorption at 430 nm. The current study is a demonstration of an efficientsynthesis of stable silver nanoparticle by gram-positive bacterial strain.

Keywords:

Biosynthesis , Silver nanoparticle , Bacterial strain