Extracellular biosynthesis and characterization of silver nanoparticles by using bacillus cereus gad 20 and their antibacterial potential against e.coli and s.aureus

The use of bacterial strains in the synthesis of silver nanoparticles emerges as an eco-friendly and exciting approach towards the field of research in life sciences. In this present work, microbial production of silver nanoparticles was investigated using the bacterial strain Bacillus cereus GAD 20. The test bacterium was isolated from soil samples from Gadchiroli district of Maharashtra state grown on Hichrome Bacillus Agar and Bacillus Differentiation Agar and further identified on the basis of 16S rRNA. Synthesized silver nanoparticles were characterized by UV-Vis spectroscopy and the maximum absorbance was found to be around λ-427nm. The particle size of silver nanoparticles was studied by Scanning Electron Microscopy (SEM). FTIR analysis confirms the presence of proteins as stabilizing agents. The antibacterial activity of silver nanoparticles was studied against multi drug resistant bacterial strains of Escherichia.coli and Staphylococcus.aureus. Zone of inhibition of microbes in presence of silver nanoparticles showed inhibition of growth suggesting antibacterial property of the silver nanoparticles.