Isotropic Silver Nanoparticles from Cytobacillus kochii Strain SW6 Isolated from Bay of Bengal Sea Sediment Water and Their Antimicrobial, Antioxidant, and Catalytic Potential.

Green synthesis of nanoparticles provides numerous advantages over physical and chemical methods because of low toxicity, high yields, cost-effectiveness, environmentally benign, and energy efficiency. Therefore, we focused on the facile and green synthesis of isotropic silver nanoparticles using the metabolic extract of Cytobacillus kochii. During synthesis, the physicochemical parameters were optimized and validated using the response surface methodology statistical tool. The presence of potent bioactive compounds that aid in the biofabrication of nanoparticles was identified in the gas chromatography-mass spectroscopy analysis and the synthesis was confirmed by surface plasmon resonance peak at 420 nm. Characterization of nanoparticles was performed by high-resolution transmission electron microscopy, Fourier transform infrared spectroscopy, dynamic light scattering, and X-ray diffraction. The synthesized nanoparticles showed potent antioxidant properties and displayed an excellent catalytic reduction potential in the degradation of hazardous dyes, such as methylene blue, phenol red, and 4-nitrophenol. Furthermore, compared to the chemically synthesized silver nanoparticles and crude extract, the biogenic silver nanoparticles exhibited a broad-spectrum antimicrobial potential. Our results demonstrate that the reported silver nanoparticles with unique characteristics might be of great promise as biomedical and catalytic agents for industrial applications.