Monday, August 2, 2010
Pacific Concourse (Hyatt Regency San Francisco)
Biosynthesis of silver nanoparticles (AgNPs) by microorganisms is environmentally friendly process with well defined chemical and physical properties and biogenic AgNPs have many biomedical applications.Saccharomyces cerevisiae and Streptomyces sp. have been used in this study for the biosynthesis of silver nanoparticles (AgNPs). The silver nanoparticles were produced after 24 h incubation of the culture supernatant of each of the two microorganisms with AgNO3 solution. The color of the mixture changed from light to dark brown after 24 h indicating the formation of AgNPs. The UV-vis spectroscopy and XRD analysis confirmed the formation of AgNPs by both microorganisms. The Transmission electron microscopy (TEM) of AgNPs samples revealed well dispersed and spherical nanoparticles with diameter ranging from 15-25 nm for Streptomyces sp. and 10-55 nm for S. cerevisiae. The AgNPs showed wide spectrum of antimicrobial activity against G+, G- and G+ spore former bacteria.