Biomimetic Synthesis of Silver Nanoparticles Using Endosymbiotic Bacterium InhabitingEuphorbia hirtaL. and Their Bactericidal Potential

Abstract

The present investigation aims to evaluate biomimetic synthesis of silver nanoparticles using endophytic bacterium EH 419 inhabiting Euphorbia hirta L. The synthesized nanoparticles were initially confirmed with change in color from the reaction mixture to brown indicating the synthesis of nanoparticles. Further confirmation was achieved with the characteristic absorption peak at 440 nm using UV-Visible spectroscopy. The synthesized silver nanoparticles were subjected to biophysical characterization using hyphenated techniques. The possible role of biomolecules in mediating the synthesis was depicted with FTIR analysis. Further crystalline nature of synthesized nanoparticles was confirmed using X-ray diffraction (XRD) with prominent diffraction peaks at 2θ which can be indexed to the (111), (200), (220), and (311) reflections of face centered cubic structure (fcc) of metallic silver. Transmission electron microscopy (TEM) revealed morphological characteristics of synthesized silver nanoparticles to be polydisperse in nature with size ranging from 10 to 60 nm and different morphological characteristics such as spherical, oval, hexagonal, and cubic shapes. Further silver nanoparticles exhibited bactericidal activity against panel of significant pathogenic bacteria among which Pseudomonas aeruginosa was most sensitive compared to other pathogens. To the best of our knowledge, present study forms first report of bacterial endophyte inhabiting Euphorbia hirta L. in mediating synthesizing silver nanoparticles.

Characterization and antimicrobial activity of silver nanoparticles mycosynthesized by Aspergillus brasiliensis

“…; Syed et al . ). The absorption band appeared at about 390–450 nm is due to the SPR of synthesized AgNPs; thus, proved the synthesis of AgNPs (Trivedi et al .…”

“…; Syed et al . ) which can bind to the AgNPs through either the cysteine residues in the proteins or free amino groups. It also proved the presence of alcohol, phenols, carbonyl and amine (both aromatic and aliphatic) and amide functional groups that would have been involved in the synthesis of the AgNPs.…”

Bio-nanobactericides: an emanating class of nanoparticles towards combating multi-drug resistant pathogens

“…Silver is considered as one of the valuable metals with a broad range of applications [8]. The usage of silver and its components can be traced down to millennia in curing diseases like ulcers and healing of wounds [39].…”

“…The bactericidal potential of silver was in practice prior to the invention of first antibiotic [40]. Till date, silver-based products are used in topical creams, disinfectants, polymer composite, dental amalgam and most of the Ayurvedic formulations consists of trace silver amount [41,42]. In recent years, with the inventions of nano-silver, their applications have gained more attention [43,44].…”

“…Different classes of nanobactericides are employed as effective agent to suppress or eradicate the microbial infections [8,9]. Nanobactericides are reported to interfere with the normal metabolic process of pathogens by destroying or inactivating the vital components required for normal cellular activities [10].…”