Antibacterial Effect of Pseudomonas sp. Biosynthesized Silver Nanoparticles on Human Pathogenic Bacteria

Abstract

The present study aimed at the biosynthesis of extracellular silver nanoparticles from Pseudomonas sp. and their characterization by means of UV-visible spectrophotometer. Moreover, the study focused on the bactericidal effects of the silver nanoparticles on human pathogenic bacteria. The nanoparticles demonstrated maximum absorbance at 410 nm corresponding to the surface plasmon resonance of nano-sized materials. However, the biosynthesis of metallic nanoparticles of silver by Pseudomonas sp. was carried out through the reduction of aqueous silver ions with culture supernatants. Pathogenic bacteria being resistant to antimicrobial agents have emerged as a major health problem in recent years. In this study, the silver nanoparticles were evaluated for their role as the antibacterial agents by well diffusion method against Pseudomonas aeroginosa, Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, Vibrio cholerae, and Staphylococcus aureus. The silver nanoparticles showed satisfactory results against all six pathogenic bacteria. The extent of bactericidal effects of these nanoparticles was analyzed through the formation of clear zones around the wells in the plates containing bacterial culture. Thus, the synthesis, characterization and application of biologically synthesized silver nanoparticles could present an important concern for the development of antimicrobial agents by pharmaceutical companies to control infectious diseases caused by different pathogenic bacteria.