Abstract

Aim of work: Silver nanoparticles play a vital role in the development of new antimicrobial substances against a number of pathogenic microorganisms. Assessment of the antimicrobial activity of biosynthesized silver nanoparticles (AgNPs) was achieved as an eco-friendly and cost-effective method alternative to complex chemical and physical techniques. Nanoparticles due to their smaller size could be very effective as they can improve the antibacterial activity through lysis of bacterial cell wall.

Methods: In the present work evaluation of extracellular biosynthesis of AgNPs by extracellular supernatant of Acinetobacter baumannii as a reducing agent was studied. Silver nanoparticles were characterized by means of UV-visible spectroscopy, Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM) and Energy dispersive X-ray microanalysis (EDX). The synthesized AgNPs were evaluated for their antibacterial activity against common pharmaceutical contaminants. The standard microorganisms designated for the study of antibacterial activity were Escherichia coli ATCC 8739, Salmonella typhimurium ATCC 6538, Klebsiella pneumonia ATCC 10031, Pseudomonas aeruginosa ATCC 15442, Bacillus spizizenii ATCC 6633, Staphylococcus aureus ATCC 6538, Candida albicans ATCC 10231 and Aspergillus niger ATCC 16404.

Results: FTIR analysis showed possible reducing the silver salt and stabilization of nanoparticles. The AgNPs surface morphology revealed from SEM images shows a formation of well-dispersed AgNPs of 45-55 nm. When AgNPs were mixed with hydrogen peroxide disinfectant they displayed strong synergistic antibacterial.

Improvement: Antimicrobial studies confirm the superior ability of biosynthesized silver nanoparticles to inhibit the growth of bacterial and fungal contaminants and their utilization in various applications particularly as antibacterial substance in disinfection and preservation to protect against various biomedical, pharmaceutical based activities.

Keywords: Silver nanoparticles, Acinetobacter baumannii, Surface plasmon resonance, Antimicrobial activity