Antibiotic and antioxidant activities biogenic silver nanoparticles synthesized using Escherichia coli (VM1) bacterium

Abstract

Synthesis of silver nanoparticles (AgNPs) using microorganisms has gained considerable attention as an efficient alternative for conventional chemical synthesis. Earlier, we have demonstrated biosynthesis of silver nanoparticles using marine Escherichia coli VM1. Here, we investigated antibacterial, antifungal and antioxidant efficacy of the synthesized silver nanoparticles using standard techniques. The results have shown that the AgNPs synthesized using the marine Escherichia coli have potential antibacterial activity against both Gram positive (Staphylococcus aureus) and Gram negative (E. coli, Klebsiella pneumoniae, S. paratyphi, Vibrio parahaemolyticus, V. cholerae and Proteus mirabilis) pathogenic bacteria and moderate antifungal activity was observed against Aspergillus niger, Penicillium sp., Trichothecium roseum and Trichophyton rubrum . Further, in vitro antioxidant study was examined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. We observed significant effect on scavenging of free radicals suggesting that the AgNPs biosynthesized using E. coli could be an efficient and eco-friendly material for biomedical applications.