Synthesis of Metallic Nanoparticles by Halotolerant Fungi

The field of nanotechnology is an immensely developing field because of its wide-ranging applications in different areas of science and technology. An important area of research in nanotechnology is the synthesis of nanoparticles by microorganisms. Although chemical methods can produce larger quantities of nanoparticles with a defined size and shape in a relatively short time, they are complicated, outdated, costly, and inefficient and produce hazardous toxic waste that are harmful not only to the environment, but also to human health. Halotolerant microorganisms represent a valuable resource of enzymes with stability in harsh conditions of pH or/and ionic strength. In this chapter, the ability of halotolerant fungi to produce nanoparticles is discussed along with the mechanisms of nanomaterial fabrication and their potential applications. To date, nanoparticle-producing halotolerant fungi synthesize mostly silver nanoparticles, followed by gold. Very few are capable of synthesizing cadmium, lead, or zinc nanoparticles. While biologically active products from halotolerant fungi represent excellent scaffolds for this purpose, there is a need to understand the mechanisms involved in the synthetic process. Another limitation of the current studies is that the experiments are conducted at laboratory scale and there are hardly any efforts on the scale-up of these processes. These shortcomings need to be addressed to harness the actual nanoparticle synthetic potential of the halotolerant to their full extent.