Microbes: Nature’s Cell Factories of Nanoparticles Synthesis

Microbes are omnipresent in environment, inhabited to specific niches and play a variety of essential roles in the natural recycling of inorganic minerals. Scientists have been trying to exploit these interactions between inorganic environment and microbes. Recently, microbes are found to synthesize inorganic nanoparticles via enzymes mediated cell activities by getting metal ions from their environment. This provided a novel breakthrough in the field of nanotechnology and directed to a new era of nano-biotechnology, where scientists are taking into account biological approaches of nanoparticles synthesis to overcome the use of expensive and toxic chemicals. Traditionally, these nanoparticles are synthesized by physical and chemical methods which pose potential hazards to health and environment. Yet it is still a challenge to synthesize nanoparticles from wide range of chemical composition and high mono-dispersity. In number of biochemical and biophysical processes, nano-biotechnology incorporates the use of actinomycetes, algae, bacteria, fungi, yeasts, and plants to produce low-cost, energy efficient and ecofriendly products. Among microorganisms, bacterial species gain more importance in synthesis of nanoparticles due to ease in their cultivation and downstream processing. This chapter provides a comprehensive overview of microbial synthesis of different nanoparticles and their biosynthesis mechanisms. Applications in the field of environment, biotechnology, biomedicine, and agriculture are also discussed.