Molecular Mechanisms that Mediate Microbial Synthesis of Metal Nanoparticles

Microbe-assisted synthesis of nanoparticles is a promising approach that provides a green, rapid, and ecologically sound strategy to fabricate potentially biogenic nanoparticles. These nanoparticles possess innate physicochemical and optoelectronic properties that render them effective in various fields of technology including biomedical, industrial, cosmetics, textiles, agricultural as well as in drug delivery. Biological synthesis routes employ various microbes such as bacteria, viruses, yeasts, actinomycetes, and fungi for the synthesis of different nanoparticles such as silver, gold, silicon, iron, zinc, platinum, and palladium. Microbial flora can generate metallic nanoparticles by either intracellular or extracellular synthesis routes. The future challenges include optimal production of nanoparticles with minimization of generation time and preferred nanoparticle structural attributes. Thus, comprehending the underlying cellular and biochemical synthesis mechanisms is imperative to designing tailor-made processes for generating optimized nanoparticles. A goal is that enhanced large-scale production and possible industrial exploitation of these generative processes will become possible. This chapter provides insights on the molecular mechanisms that encompass enzymatic and nonenzymatic production of different types of nanoparticles along with the physicochemical factors involved in the process.