African Journal of Biotechnology Research

African Journal of Biotechnology Research ISSN 9316-2194 Vol. 4 (9), pp. 212-220, September, 2016. © International Scholars Journals

Full Length Research Paper

Extracellular synthesis of metallic nanomaterials through the use of biological components

Asha B. Subbulakshmi2, Deepek R. Chandra1*, and R. P. Sreedharan2

1Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati-781039, Assam, India,

2Plant Biotechnology Laboratory, Centre for Advanced Studies in Botany, North Eastern Hill University, Shillong, India


Accepted 25 August, 2016


Bacillus megaterium isolated from fluvial zone of North Bihar has been used for the extracellular synthesis of metal nanoparticles (NPs) viz silver, lead and cadmium. The synthesized nanoparticles got accumulated on the surface of the cell wall of bacteria. Bacillus megaterium was grown aerobically and the cultures were challenged with the solutions of silver nitrate, lead nitrate and cadmium nitrate in requisite ambience of laboratory. Cell lysate obtained, after the centrifugation of cultures were characterized through optical absorption by UV-Vis Spectrophotometer, X-ray Diffraction (XRD), Transmission Electron Micrography (TEM) and Energy Dispersive Spectroscopy (EDS). These nanoparticles of Ag, Pb and Cd showed absorption peaks at ~ 435 nm, ~ 330 nm and ~ 410 nm respectively corresponding to the plasmon resonance of silver nanoparticles (AgNPs), cadmium nanoparticles (CdNPs) and lead nanoparticles (PbNPs). XRD Spectrum of these nanoparticles confirmed the formation of Ag, PbS and CdS particles by showing their respective characteristic peaks. TEM showed the production of these metal nanoparticles with particle size in the range of 10-20 nm.

Keywords: Extracellular; AgNPs; CdNPs; PbNPs; TEM; Selected Area Electron Diffraction