Synthesis of nanoparticles using microorganisms

The total global demand for nanoscale materials, tools and devices was estimated at nearly $7.5 billion in 2003 and is expected to reach $28.7 billion in 2008, at an average annual growth rate of 30.6%. Although nanoparticle synthesis has been accomplished by chemical methods, there is an ever-growing need to develop clean, nontoxic, and environmentally benign synthesis procedures. In this regard the use of microorganisms such as bacteria and fungi in the biosynthesis of metal nanoparticles and their applications holds immense potential. Exposure to extreme environmental conditions, including the presence of high concentrations of toxic metalions and metals, forces microorganisms to resort to specific defense mechanisms to quell stresses. Production of metal nanoparticles, as a form of isolation or sequestration of toxic substances forms the basis for important applications of microorganisms including synthesis of nanoparticles. Certain strains of microorganisms tolerate heavy metal stress and have potential to serve as biofactories for the synthesis of metal nanoparticles. At TERI, researchers have identified isolates of mycorrhizal fungi, other fungi and bacteria with such tolerance and provide the initial experimental models to text accumulation of high levels of various heavy metalsvia nanoparticle formations.

TERI's present research in nano-science involves the use of these efficient microbial strains for the synthesis of nanosized materials. Under the activity of the ongoing project the suitable isolates are being screened and subsequently tested for synthesis of nanoparticles. Few bacteria and fungal isolates have been selected for their ability to synthesize Chromium and Lead nanoparticles. Metal accumulation as nanoparticle was confirmed through the transmission electron microscopy (TEM) and energy dispersive X-ray (EDX) confirmed the metal presence in cell.

Chromium nanoparticle

TEM micrographs recorded from thin section of Paxillus invlutus fungus cells after reaction with Cr ions for 72 hrs at different magnification.

Sponsors: Department of Biotechnology (DBT)
Duration: 3 years
Energy Dispersive X- Ray Analysis (EDX) spectrum of Paxillus invlutsu fungi for Cr nanoparticle
Posted on: 19 April 2010  |   Project status: Completed