International Journal of Pharmaceutical Research and Bio-Science
Abstract
The microorganisms such as bacteria, yeast and now fungi play an important role in remediation of toxic metals through redn. of the metal ions, this was considered interesting as nanofactories very recently. Using these dissimulatory properties of fungi, the biosynthesis of inorg. nanomaterials using eukaryotic organisms such as fungi may be used to grow nanoparticles of gold and silver intracellularly in Verticillium fungal cells. Recently, it was found that aq. chloroaurate ions may be reduced extracellularly using the fungus F. oxysporum, to generate extremely stable gold or silver nanoparticles in water. The study of biosynthesis of nanomaterials offers valuable contribution into materials chem. The ability of some microorganisms such as bacteria and fungi to control the synthesis of metallic nanoparticle should be employed in the synthesis of new materials. The biosynthetic methods are investigated as an alternative to chem. and phys. ones. It is known that many microorganisms can provide inorg. materials either intra- or extra-cellularly. For example, bacteria Pseudomonas strutzeri isolated from silver mine is able to reduce Ag+ ions and accumulates silver nanoparticles. The size of such nanoparticle was 16-40 nm, with an av. diam. 27 nm. Moreover, silver is occasionally used in the medical field as a topical bactericide. With the progress of nano-technol., many labs. around the world have investigated silver nanoparticle prodn. as the nanoparticle possesses more surface atoms than a microparticle, which greatly improves the particle's phys. and chem. characteristics. However, at present there is no truly efficient method for their large-scale prodn. Some phys. or chem. methods that are currently available for silver nanoparticle prodn. include mech. smashing, a solid-phase reaction, freeze-drying, spread drying and pptn. (co- and homo-pptn.). In general, these methods consume a lot of energy in order to maintain the high pressures and temps. that are needed for them to work. In contrast, many bioprocesses occur under normal air pressure and temp., resulting in vast energy savings
