Comparison of Antimicrobial Properties of Silver Nanoparticles Synthesized from Selected Bacteria

Abstract

Green silver nanoparticle (AgNP) biosynthesis is facilitated by the enzyme mediated reduction of Ag ions by plants, fungi and bacteria. The antimicrobial activity of green AgNPs is useful to overcome the challenge of antimicrobial resistance. Antimicrobial properties of biosynthesized AgNPs depend on multiple factors including culture conditions and the microbial source. The antimicrobial activity of AgNPs biosynthesized by ATCC 27853, ATCC 25922, ATCC 25923 and (confirmed clinical isolate) were investigated in this study. Biosynthesis conditions (AgNO concentration, pH, incubation temperature and incubation time) were optimized to obtain the maximum AgNP yield. Presence of AgNPs was confirmed by observing a characteristic UV-Visible absorbance peak in 420-435 nm range. AgNP biosynthesis was optimal at 0.4 g/L AgNO concentration under alkaline conditions at 60-70 °C. The biosynthesized AgNPs showed higher stability compared to chemogenized AgNPs in the presence of electrolytes. AgNPs synthesized by were the most stable while NPs of were the least stable. AgNPs synthesized by and showed good antimicrobial potential against MRSA and. AgNPs synthesized by had greater antimicrobial activity. The antimicrobial activity of NPs may vary depending on the size and the morphology of NPs.

Bacteria mediated silver nanoparticles: comparison as potent antibiofilm agents

“…14 Further characterization of biosynthesized AgNPs using FT-IR spectroscopy indicated NH stretch vibrations present in the amide linkages of primary and secondary amines of proteins, presence of nitrocompounds from proteins or enzymes, C-H symmetrical stretch vibration of alkanes and -C-N-stretching vibrations confirming that the attached proteins in the biosynthesized AgNPs support stabilization of AgNPs. 15 In the present study, silver nanoparticles synthesised by all four bacterial species demonstrated over 50% biofilm inhibition at a AgNP concentration between 1.98 mg/ml to 0.225 mg/ml (Fig. 3).…”

Antimicrobial Nanoparticles: applications and mechanisms of action

“…Bacteria, fungi and plants have recently gained much attention due to their ability to biosynthesize metal NPs by an environmentally friendly process. For example, silver nanoparticles have been successfully made from Staphylococcus aureus, Pseudomonas aeruginosa, 7 Escherichia coli, Acinetobacter species, 8 Lactobacillus species, 9 Klebsiella pneumoniae 10 and Enterobacter cloacae 11 . An advantage of biological synthesis methods is the higher stability of the AgNPs compared to chemically synthesized NPs.…”

Biofabrication of isotropic silver nanoparticles using cell-free metabolic extract of Bacillus kochii, and evaluation of their antimicrobial, antioxidant and catalytic potentials

“…Against A. baumannii, BkCE-AgNPs showed higher ZOI than standard streptomycin of the same concentration and higher inhibition zone than AgNPs synthesis using Discorea bulbifera (Chopade et al 2013). BkCE-AgNP ZOI against P. aeruginosa was equal to AgNPs synthesized using Ipomea carnea (Daniel et al 2014)) and more than AgNPs synthesized using E. coli and S. aureus (Peiris et al 2018). BkCE-AgNPs showed a 13.5 mm ± 0.5 zone against S. aureus, which was more signi cant than the chemically synthesized AgNPs using sodium borohydride (Vu et al 2018).…”