Actinobacterial-Mediated Fabrication of Silver Nanoparticles and Their Broad Spectrum Antibacterial Activity Against Clinical Pathogens.

The aim of this study is to fabricate silver nanoparticles (AgNPs) using actinobacterial strain isolated from lawn soil. Among six isolates, one isolate named AS-3 was potent in AgNPs production; hence it was identified deployed on gene sequence (16S rRNA) as Streptomyces spongiicola AS-3 (99.8% similarity). Actinobacteria mediated synthesized AgNPs were analyzed using UV-visible spectroscopy (UV-Vis), which showed a Surface Plasmon Resonance (SPR) at around λ = 443 nm. Scanning electron microscopy (SEM) analyses revealed the occurrence of predominant spherical AgNPs with polydispersed, with an average size of 22 nm. Energy-dispersive X-ray spectroscopy (EDS) established the existence of silver component. While the Fourier transforms infrared spectroscopy (FTIR) evidenced the occurrence of proteins as the bio reduction and topping agents over the AgNPs. X-ray diffraction (XRD) examination confirmed the obtained AgNPs were in crystalline planes of the face centric cubic. The S. spongiicola AgNPs antibacterial activity showed a broad spectrum antibacterial action against Staphylococcus aureus, Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, Vibrio cholera, Shigella sp., and Salmonella typhi were confirmed by disc diffusion test and MIC analysis.