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Introduction: Attention to the biosynthesis of nanoparticles (NPs) has been increased recently since they are cost-effective, eco-friendly, and potential alternatives to chemical and physical methods. This study aimed to synthesize zinc oxide nanoparticles (ZnO NPs) using an intracellular extract of Saccharomyces cerevisiae. Moreover, it was attempted to evaluate their antibacterial and antioxidant effects.
 
Materials & Methods: After the preparation and identification of the physical characteristics of the ZnO NPs, their antioxidant activity was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Ferric Reducing Ability of Plasma (FRAP). Moreover, the antibacterial activity of NPs was tested against Gram-positive bacteria (Staphylococcus aureus and Listeria monocytogenes) and Gram-negative bacteria (Escherichia coli) using a disc diffusion method. Ethics code: IR.ausmt.rec.1398.11.33
Findings: The results showed that the synthesized NPs had a spherical shape, and their diameter size was < 30 nm. A good absorption at 370 nm confirmed the presence of ZnO NPs. These NPs depicted an improved antibacterial activity against S. aureus. Moreover, they showed concentration-dependent antioxidant activity in both DPPH and FRAP.
 
Discussions & Conclusions: The results indicated that the biosynthesized ZnO NPs had antibacterial and antioxidant activities. This suggests that ZnO NPs can be used in food packaging and cosmetic products. In addition, they can be utilized as an alternative to synthetic antibiotics. However, further studies are required to be conducted in this regard.