In vitro antibacterial activity of biosynthesized silver nanoparticles against gram negative bacteria

Abstract

Biosynthesis of silver nanoparticles (AgNPs) has been performed using various sources including plants and fungi. Sargassum swartzii is an alga that has a vast spectrum of biological activities and is predominantly found on the Indian coasts. In this study, AgNPs was biosynthesized using S. swartzii and evaluated for its antibacterial potency against Escherichia coli (ATCC 25922). The synthesized nanoparticles (NPs) were imaged using TEM analyses and found to be predominantly spherical and crystalline with size around 20–40 nm. The Zeta sizing analysis revealed mean particle size to be 40.4 nm. The XRD analysis revealed the particles are crystalline nature and average size around 54 nm. The biosynthesized AgNPs were used against treating E. coli and it was found to cause a considerable amount of deterioration to the microbes when observed under AFM and FE–SEM. The study revealed the significant antibacterial activity of the synthesized AgNPs due to extensive membrane damage.