Synthesis of Biosurfactant Stabilized Silver Nanoparticles, Characterization and Their Potential Application for Bactericidal Purposes

Publication date: Available online 15 February 2020Source: Journal of Hazardous MaterialsAuthor(s): Fisseha A Bezza, Shepherd M Tichapondwa, Evans MN ChirwaAbstractUniformly dispersed silver nanoparticles (AgNPs) with remarkable colloidal stability were synthesized using chemical reduction method in lipopeptide biosurfactant reverse micelles. Transmission Electron microscopy (TEM), Scanning electron microscopy (SEM) and UV–vis spectroscopy analysis exhibited monodisperse nanoparticles with spherical morphology of diameter of 21 ± 2. The lipopeptide stabilized AgNPs displayed remarkable antibacterial activity with minimum inhibitory concentration (MIC) values of 15.625 µg/mL against Gram-negative Pseudomonas aeruginosa CB1 and Gram-positive Bacillus subtilis CN2 strains with a significant dose-dependent reduction of cell viability and loss of membrane integrity. Investigation of AgNPs internalization and dissolution assays demonstrated 42-fold higher leaching of the lipopeptide-stabilized AgNPs compared to the bare AgNPs, and concentration dependent increase in cellular uptake with subsequent damage to intracellular organelles. Further ultrastructural observation using TEM revealed internalization and strong binding of considerable amount of AgNPs on the lipopolysaccharide layer of the Gram-negative and peptidoglycans layer of Gram-positive bacteria indiscriminately, demonstrating robust antibacterial activity and potential application to treat multidrug resistant ba...
Source: Journal of Hazardous Materials - Category: Environmental Health Source Type: research