Antimicrobial activity of PVP coated silver nanoparticles synthesized by Lysinibacillus varians

Emergence of resistant microbes to conventional antibiotics and increased emphasis on health-care costs has raised the concern for the development of new effective antimicrobial reagents. Silver nanoparticles being an excellent broad-spectrum antibacterial agent could be considered as a suitable alternative for existing antibiotic. This study demonstrates the extra-cellular synthesis of stable silver nanoparticles using supernatant of Lysinibacillus varians. The synthesized silver nanoparticles were characterized by using UV-visible spectrum analysis, X-ray diffraction, Transmission electron microscopy (TEM) and FT-IR analysis. The synthesized silver nanoparticles showed a peak around 420 nm. TEM analysis revealed that the size of silver nanoparticles was in the range of 10-20 nm. Silver nanoparticles carry a charge of -39.86 mV, which confirmed the stability of silver nanoparticles. The biologically synthesized silver nanoparticles showed antimicrobial activity against Gram-positive, Gram-negative bacteria and fungi. Therefore, the current study reveals an efficient and eco-friendly synthesis of silver nanoparticles by L. varians with potent antimicrobial activity.