Paper Title
Biosynthesis, Characterization and Applications of Zinc Oxide Nanoparticles Using Bacillus Mycoides

Abstract
The development of rapid and reliable processes for the synthesis of nano-sized materials is of great importance in the field of nanotechnology. The present study deals with healthy correlation between the metal tolerance ability of bacterial isolates and its ability to synthesize Zinc oxide (ZnO) nanoparticles. A total of twenty-three bacterial cultures were isolated from four zinc contaminatedsoil samples collected from in the close vicinity of zinc electroplating industries situated in Satpur MIDC of Nashik city, Maharashtra (INDIA). Among all twenty-three isolates, isolate SB3 was found to have maximum metal tolerance of 1000µg/mL which was identified as Bacillus mycoides on basis of morphological and biochemical characters and confirmed using VITEK 2 system version 05.02.The extracellular biosynthesis of ZnO nanoparticles was performed using Bacillus mycoides and 1mMZinc sulphateheptahydrate as a precursor. Recovery of nanoparticles was done using a mixture of CTAB and Hexane in the ratio 2:1 respectively. The synthesized ZnOnanoparticles were further characterized by using UV- Visible double beam spectroscopy, Fourier Transform Infrared (FTIR) Spectroscopy, X- ray diffraction analysis (XRD) and Scanning electron microscope (SEM) confirming the crystalline spherical structure of ZnO nanoparticles having Z-average of 55nm. These nanoparticles were found to have significant antimicrobial property and the Minimum Inhibitory Concentration (MIC) against selected pathogenic strains ofStaphylococcus aureus, Streptococcus pyogenesand Klebsiella pneumoniaewas found to be 25µg/mL, 25µg/mL and 50µg/mLrespectively. % Free radical scavenging activity of 100µg/ml of zinc nanoparticles assayed using DPPH was found to be 83.33%. Photocatalytic decolorization of 50ppm Methylene Blue (MB), Congo Red(CR) and Malachite Green(MG) was studied using free and immobilized nanoparticles by UV- visible spectroscopy. % Photocatalytic activity of free ZnO nanoparticles on decolorization of MB, CR and MG was obtained as 89.66%, 92.35% and 88.56% respectively. % Decolorization of MB, CR and MG using sodium alginate encapsulated ZnO nanoparticles was found to be 84.37%,86.93% and 79.45% respectively. Encapsulated ZnO nanoparticlescouldbe reused for Photocatalytic decolorization of dyes with significant results till about three cycles. Keywords - Zinc oxide nanoparticles, electroplating industry, metal tolerance ability, MIC, free radical scavenging effect, photocatalytic decolorization of dyes