Inhibition of Aflatoxin Production by Nanosilver

Aflatoxins (AFs) are a group of highly oxygenated polyketidese-derived mainly produced by Aspergillus flavus and Aspergillus parasiticus, whose biosynthesis mechanisms are extremely sophisticated. Nanosilver exhibits remarkably unusual physical, chemical and biological properties. The major property of nano-silver materials is their antibacterial effect. However, there is no information regarding this antibacterial effect of silver nanomaterial when used by ordinary people. Further, nanosilver is used for treatment of wounds and burns or as a contraceptive and marketed as a water disinfectant and room spray. Thus, use of nanosilver is becoming more and more widespread in medicine and related applications and due to increasing exposure toxicological and environmental issues need to be raised. The resent study aimed to investigate the effect of nanometer sized silver on the development of Aspergillus flavus and its aflatoxin production. The commercial nanometer sized silver was analyzed in the Ag+ ion form. The growth rate decrease in the nano-silver exposed groups; furthermore, the morphology of colonies of nano-silver exposed Aspergillus flavus also changed and the production of aflatoxin reduced as well. Therefore, the Ag+ ions in commercial nanometer sized silver could accumulate in the cells of fungus and seriously damage the production pathway of aflatoxin. Thus, the present study indicates nano-Ag may have considerable antifungal activity, deserving further investigation for clinical applications.