TiO₂ Nanoparticles from Baker's Yeast: A Potent Antimicrobial.

Titanium dioxide (TiO2) has wide applications in food, cosmetics, pharmaceuticals and manufacturing due to its many properties such as photocatalytic activity and stability. In this study, the biosynthesis of TiO2 nanoparticles (NPs) was achieved by using Baker's yeast. TiO2 NPs were characterized by X-ray Diffraction (XRD), UV-Visible spectroscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray analysis (EDX) studies. The XRD pattern confirmed the formation of pure anatase TiO2 NPs. According to EDX data Ti, O, P and N were the key elements present in the sample. SEM and TEM revealed that the nanoparticles produced were spherical in shape with an average size of 6.7 ± 2.2 nm. The photocatalytic activity of TiO2 NPs was studied by monitoring the degradation of methylene blue dye when treated with TiO2 NPs. TiO2 NPs were found to be highly photocatalytic comparable to commercially available 21 nm TiO2 NPs. This study is the first report on antimicrobial study of yeast-mediated TiO2 NPs synthesized using TiCl3. Antimicrobial activity of TiO2 NPs was greater against selected Gram-positive bacteria and Candida albicans when compared to Gram-negative bacteria both in the presence or absence of sunlight exposure. TiO2 NPs expressed a significant effect on microbial growth. The results indicate the significant physical properties and the impact of yeast-mediated TiO2 NPs as a novel antimicrobial.