Bactericidal potential of silver nanoparticles synthesized using cell-free extract of Comamonas acidovorans: in vitro and in silico approaches

Abstract

The need to overcome human threats from pathogenic microbes, development of nanomaterials have been provoked for a new generation of antimicrobials. In the present study, biosynthesis of silver nanoparticles (AgNPs) was acquired using Comamonas acidovorans extract within 72 h under static condition. Electron microscopy studies revealed that the size of AgNPs was ranging from 6-53 nm and had spherical, oval and irregular shapes with smooth surfaces. Prepared AgNPs interacted with proteins, carbohydrates and other aromatic molecules. Biosynthesized AgNPs were bactericidal, which significantly inhibited pathogenic microbes, i.e., Streptococcus pyogenes, Staphylococcus aureus and Escherichia coli. Higher concentrations of AgNPs (20 lg ml -1 ) inhibited 92-98% growth of all tested bacteria within 24 h. AgNPs-protein network studies carried out to recognize the protein interactions with AgNPs and to understand probable bactericidal mechanisms. AgNPs may penetrate into cell through membrane proteins and damage them by modifying amino acids. Due to AgNPs-protein interactions, dysfunctions in enzymes obstruct certain metabolic processes, which cause the bacteria to die eventually. In certain pathogenic microbes, cue and cus systems detoxify Ag ? ions, transport through transporter proteins and expel them to the extracellular space, which are mainly responsible for Ag resistance.

Laccase-conjugated amino-functionalized nanosilica for efficient degradation of Reactive Violet 1 dye

“…The absorbance shift of nanosilica that was changed due to the laccase was crosslinked with nanosilica. The FTIR spectrum of laccase nanoparticle showed a peak at 2935/cm for C-H stretching, confirming cross-linking of laccase with nanosilica by glutaraldehyde molecule [28].…”

“…Among them, microbes and plants have been used for decades as a biosensor for the toxicity of environmental pollutants [28,41]. Evaluating the microbial toxicity of RV 1 dye on agricultural important micro-organisms like R. radiobacter and Azotobacter sp.…”

Biosorption Potential of Phanerochaete chrysosporium for Arsenic, Cadmium, and Chromium Removal from Aqueous Solutions

“…[30] The peaks at 2925 and 2854 cm −1 are assigned for asymmetric and symmetric vibrations of CH 3 groups presented in fungal proteins are assigned in control fungal biomass. [33] The peaks at 1381, 1150, and 1042 cm −1 are due to CH 3 wagging (umbrella deformation), symmetric SO 3 stretching and COH stretching vibrations. Cd, Cr, and mixed metal absorbed biomass marginally shifted for amide I (1644 cm −1 ), amide II (1564 cm −1 ), and amide III (1247 cm −1 ) presented in proteins, revealing the proteins of these samples highly interacted with metals.…”

“…Cd, Cr, and mixed metal absorbed biomass marginally shifted for amide I (1644 cm −1 ), amide II (1564 cm −1 ), and amide III (1247 cm −1 ) presented in proteins, revealing the proteins of these samples highly interacted with metals. [33] 600-800 cm −1 region corresponded to the metal-CH 3 binding, which mostly showed the interactions between metals and biological components, i.e., proteins, fatty acids, and/or carbohydrates. [33] The peaks at 1381, 1150, and 1042 cm −1 are due to CH 3 wagging (umbrella deformation), symmetric SO 3 stretching and COH stretching vibrations.…”

“…In fungal cell walls, chitin and its associated polysaccharides contain carbonyl groups, which are also assigned at 1644 cm −1 . [33] The peaks at 1381, 1150, and 1042 cm −1 are due to CH 3 wagging (umbrella deformation), symmetric SO 3 stretching and COH stretching vibrations. [32] Intensity of PO (phospholipids) and CO stretching (polysaccharides) is increased in Cd, Cr, and mixed metal biomass samples as compared to As and control samples.…”