Department of Microbiology, Kakatiya University, Warangal, 506009,Andhra Pradesh, India

Metal-tolerant microorganisms have been exploited in recent years to synthesize nanoparticles due to their potential to offer better size control through peptide binding and compartmentalization. Biological synthesis of silver nanoparticles using microorganisms has received profound interest because of their potential to synthesize nanoparticles of various size, shape and morphology. In the Present study, synthesis of silver nanoparticles by a bacterial strain PSK09 isolated from marine cost is reported. Molecular identification of the isolate showed it as a strain of Pseudomonas aeruginosa. On treating the bacteria with 1 mM AgNO3, it was found to have the ability to form silver nanoparticles  at room temperature within 24 h. SNPs were characterized by UV-visible spectrophotometry, X-ray diffraction (XRD), and scanning electron microscopy (SEM). UV-visible absorption scan of a 48 h culture exposed to 5mM silver nitrate revealed a broad peak at 450nm indicative of the surface plasmon resonance of SNPs. This was confirmed by the visual observation and UV–Vis absorption at 450 nm. Therefore, the current study is a demonstration of an efficient synthesis of stable silver nanoparticle by a bacillus strain.

Keywords: Nanoparticles, scanning electron microscopy, X-ray diffraction, UV-visible spectrophotometry, Pseudomonas aeruginosa