ABSTRACT
There is growing need to develop clean, non-toxic and environmentally friendly (“green chemistry”) procedures for synthesis and assembly of nanoparticles (NPs). The use of biological organisms in this area is rapidly gaining importance due to their ecological significance, high success rates and ease in formation of nanoparticles. The advantages associated with the use of microorganisms, for biosynthesis of metal NPs, have attracted researchers to elucidate the mechanisms of metal ion uptake, its bioreduction, NP formation and decipher the role of microbial enzymes in the formation of NPs. Bacteria have been known to enrich ions, synthesize magnetite crystals, reduce Ag+ into metal particles, form nanoparticles as well as octahedral gold and, recently, ceramic to metal composites. This review focuses on the effective and efficient synthesis of metallic nanoparticles by bacteria while exploring their various prospective applications, as nanofertilizers and plant protectants, besides trying to understand the current scenario in the debates on the toxicity issues of these nanoparticles.
