The biosynthesis of nanoparticles using microorganisms has recently attracted the great interest of the scientific community; it is considered an excellent approach for the synthesis of nanoparticles as compared to the traditional chemical and physical methods. Microorganisms-mediated production of nanomaterial provides an even greater boost to green biotechnology. Biogenic nanomaterials have shown enhanced properties in terms of mechanical, physical, and chemical due to their unique nanoscale behavior. Nanoparticles synthesized with the help of microorganisms have primarily been used as a carrier for economically important biomolecules for example enzymes, proteins, therapeutic drugs, etc. Over and above, in recent years microorganism-assisted nanomaterial has been recruited for the bioremediation of various industrial effluents and toxic pollutants. Nowadays, soil and water contamination heavily increases with organic/inorganic composites, and it is a worldwide issue for food safety and the environment. In this chapter, we are giving an overview of microbial nanotechnology and its applications, due to the small size, and catalytic activities nanoparticles have been used effectively to remediate the contaminated soil and water. Microbial nanotechnology may act as a sustainable, cost-effective, and eco-friendly solution to most of the environmental cleanup issues, agriculture and food.