Maryam Tabibi - Department of Microbiology, Qom Branch, Islamic Azad University, Qom, Iran
Seyed Soheil Agaei - Department of Microbiology, Qom Branch, Islamic Azad University, Qom, Iran
Mohammad Ali Amoozegar - Extremophiles Laboratory, Department of Microbiology, Faculty of Biology and Center of Excellence in Phylogeny of Living Organisms, College of Science, University of Tehran, Tehran, Iran
Razieh Nazari - Department of Microbiology, Qom Branch, Islamic Azad University, Qom, Iran
Mohammad Reza Zolfaghari - Department of Microbiology, Qom Branch, Islamic Azad University, Qom, Iran

Background & Aims of the Study: Selenium is an essential nutritional material used for the important functions of the human body. The issue of the production of selenium nanoparticles (SeNPs) was investigated in various fields, such as anticancer, antioxidant, and antibacterial activities. Materials and Methods: In order to study antibacterial activity, the nutrient broth medium containing synthesized SeNPs in six different concentrations (i.e., 100, 50, 25, and 12.5 µM) was evaluated on six pathogenic bacteria. Then, the growth curves were drawn as an antibacterial assay in six pathogenic bacteria. In addition, the antioxidant effect was examined by the 2, 2-Diphenyl-1-picrylhydrazyl method. The stock solution of SeNPs was mixed with culture media in six different concentrations (i.e., 0.001, 0.01, 0.1, 1, 10, and 100 μM) and exposed on MCF-7 and HT-29 cell lines; therefore, the anticancer effects of SeNPs were assayed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. Results: According to the obtained results, the most and least significant antibacterial effects of synthesized SeNPs were observed for Staphylococcus aureus (98%) and Klebsiella pneumonia (51.55%), respectively. The highest concentration of biosynthesized SeNPs can achieve a better outcome regarding the antioxidant activity. The growth of MCF-7 and HT-29 cancer cell lines were inhibited by synthesized SeNPs in a concentration of 100 µM. Conclusion: Consequently, the results of the present study showed that SeNPs synthesized from indigenous halophilic bacteria could display anticancer, antioxidant, and antibacterial activities. This progress can assist in the treatment of different diseases.

Antibacterial agents, Anticancer, Antioxidants, Halophile, Nanoparticles, Selenium