BIOSYNTHESIS, CHARACTERIZATION AND APPLICATION OF SILVER NANOPARTICLES BY GEOBACILLUS THERMODENITRIFICANS AZ1 AS ANTIMICROBIAL, ANTIBIOFILM AND DYE CATALYISTASMAA M. YOUSSIF, NADIA A. SOLIMAN, SORAYA A. SABRY AND HANAN A. GHOZLANAbstract Silver nanoparticles are playing an important role in biomedical and various applications. Bacteriogenic synthesis of nanoparticles emerges as an eco-friendly and exciting approach. In this work, we demonstrate for the first time the extracellular biosynthesis of AgNPs from the Thermophilic Geobacillus thermodenitrificans. The plasmon surface resonance of biosynthesized Ag-NPs showed its characteristic peak at 410 nm. Fourier transform infrared spectrometer (FTIR) analysis confirmed the nature of the capping agents as protein. X-ray diffraction (XRD) and TEM analysis confirmed the purity, spherical and size (1.44 â 16.3 nm) of Ag-NPs. Energy-dispersive X-ray spectroscopy (EDX) data validated the biological synthesis of Ag-NPs. The nanoparticles showed highest antimicrobial activity against Candida albicans and to a lesser extent towards Staphylococcus aureus and Klebsiella pneumonia. The possible use of NPs (0.15 mg/mL) for biofilm eradication was also documented against S.aureus and P.aeruginosa (80â90 % inhibition, respectively). In presence of solar energy, 64% degradation of methyl orange (MO) was achieved upon treatment with G. thermodenitrificans AZ1 AgNPs. |