Extracellular Synthesis of Silver Nanoparticles by Gram-positive bacterial strain

Abstract

Silver nanoparticles (SNPs), are among the most popular nanomaterials due to their unique physical and chemical properties. Synthesis of nanoparticles by physical and chemical approaches are eco-unfriendly and 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 isolated from soil samples. A gram positive bacterial strain resistant to silver nitrate was selected for the synthesis of AgNPs. The supernatant of bacterial strain was added to the reaction solution containing 1mM of silver nitrate. After the color change, reaction solution was analyzed using UV–Vis spectrophotometer. Among the bacterial isolates and purified from soil samples, a bacterial isolated was randomly selected for the ability to form silver nanoparticles. This was confirmed by formation of brown colour and the visual observation and UV–Vis absorption at 430 nm. The current study is a demonstration of an efficient synthesis of stable silver nanoparticle by gram-positive bacterial strain.