Abstract

Biological Synthesis of Silver Nanoparticles and Its Antibacterial Activity

Hinal Gandhi and Shabib Khan

The ability of prokaryotic microorganisms to reduce the inorganic metals has opened up an exciting ecofriendly approach towards the development of green nanotechnology. Thus synthesis of metal nanoparticles through biological approach is an important aspect of current nanotechnology. In this study, silver nanoparticles have been successfully synthesized by Escherichia coli, in which exposure of supernatant to silver ions resulted in the extracellular reduction of the metal ions and formation of silver nanoparticles. Antimicrobial activity of silver nanoparticles was evaluated for their combined effects with antibiotics against microbes. The antibacterial activities increased in the presence of biologically synthesized silver nanoparticles. The enhancing effect was observed for Bacitracin against Escherichia coli and Salmonella paratyphi B., for Ampicillin against Corynebacterium diphtheriae, for Kanamycin against Klebsiella pneumonia, for gentamycin against Pseudomonas aeruginosa and for Bacitracin, Gentamycin, Erythromycin, Ciprofloxacin against Staphylococcus aureus.