A Comparative Nano Biotechnological Study: pH Dependent Biosynthesized Silver Nanoparticles by Aspergillus Niger, Aspergillus Flavus and Streptomyces Fradiae

Silver nanoparticles were biosynthesized by A. nger, A. flavus and S. fradiae with extracellular process. Maximum biosynthesized AgNPs was recorded by S. fradiae at pH9. Size and shape of biosynthesized AgNPs were examined using transmission electron microscope (TEM). Spherical nanoparticle was the most common shape at pH 9 with smallest size of 21.34 nm. The antibacterial activity of AgNPs was examined against E. coli, Pseudomonas sp. and Klebsiella sp. S. fradiae nanoparticles showed maximum antibacterial activity against E. coli and Pseudomonas sp. While AgNPs biosynthesized by A. niger exhibited greater inhibition zone diameter toward the growth of Klebseilla sp. In vitro studying the effect of AgNPs on hemolysis of human red blood cells has revealed a very low hemolytic activity, where S. fradiae considered the most little hemolytic one (5.65 %). AgNPs have a potential antibacterial with negligible hemolytic activity and low cost, so it can be used safely as effective antimicrobial agent.