ABSTRACT
Silver nanoparticles have many applications in medicine, pharmaceutical and health sciences. There are some problems in physical and chemical methods of nanoparticle production including high cost, environmental pollution and complexity of these processes, while the biological production methods are economical and eco-friendly. The aim of this study was biosynthesis of silver nanoparticles by Bacillus bacteria. The gender of Bacillus bacteria was isolated from Ainaly territory soil and copper mines of Ahar city [Sungun and Mazraeh] using morphological observation and some preliminary biochemical tests. The isolated bacteria were suspended in 50 ml of 3.5 mM aqueous AgNo3 solution at pH 7 for 48-72 h. After color changing observation, the solutions were centrifuged to prepare biomass for analyses of UV-vis spectrophotometer and TEM. The molecular test was performed to confirm the gender of the bacteria. After isolation of 40 kinds of Bacillus bacteria category, just the one from Sungun Copper Mine was found to be able to produce silver nanoparticles. The colour changing of aqueous medium and the result of UV-vis spectrophotometer demonstrated the formation of silver nanoparticles. TEM micrographs indicated spherical silver nanoparticles with the size range of 20-50 nm. The molecular test demonstrated the genus of bacteria as Bacillus. The results showed that the isolated species of Bacillus is able to produce sliver nanoparticles.