Antioxidant and antimicrobial activities of Spirulina platensis extracts and biogenic selenium nanoparticles against selected pathogenic bacteria and fungi

Abdel-Moneim Eid Abdel-Moneim; Mohamed T El-Saadony; Abdelrazeq M Shehata; Ahmed M Saad; Sami Ali Aldhumri; Sahar M Ouda; Noura M Mesalam

doi:10.1016/j.sjbs.2021.09.046

Antioxidant and antimicrobial activities of Spirulina platensis extracts and biogenic selenium nanoparticles against selected pathogenic bacteria and fungi

Saudi J Biol Sci. 2022 Feb;29(2):1197-1209. doi: 10.1016/j.sjbs.2021.09.046. Epub 2021 Sep 17.

Authors

Abdel-Moneim Eid Abdel-Moneim¹, Mohamed T El-Saadony², Abdelrazeq M Shehata³, Ahmed M Saad⁴, Sami Ali Aldhumri⁵, Sahar M Ouda^{5

6}, Noura M Mesalam¹

Affiliations

¹ Biological Applications Department, Nuclear Research Center, Egyptian Atomic Energy Authority, 13759, Egypt.
² Department of Agricultural Microbiology, Faculty of Agriculture, Zagazig University, Zagazig 44511, Egypt.
³ Department of Animal Production, Faculty of Agriculture, Al-Azhar University, Cairo 11651, Egypt.
⁴ Biochemistry Department, Faculty of Agriculture, Zagazig University, Zagazig 44511, Egypt.
⁵ Department of Biology, Khurmah University College, Taif University, 11099, Taif 21944, Saudi Arabia.
⁶ Plant Research Department, Nuclear Research Center, Egyptian Atomic Energy Authority, 13759, Egypt.

Abstract

This study investigated the antimicrobial and antioxidant activity of three Spirulina extracts (methanol, acetone, and hexane) and the biological selenium nanoparticles (SeNPs) fabricated by Bacillus subtilis AL43. The results showed that Spirulina extracts exhibited antimicrobial activity against tested pathogens. Besides, Spirulina extracts significantly scavenged ABTS and DPPH radicals in a dose-dependent manner. The methanolic extract had higher total phenolic content, antimicrobial activity, and antioxidant activity than other extracts. The selenium nanoparticles were synthesized by Bacillus subtilis AL43 under aerobic conditions and were characterized as spherical, crystalline with a size of 65.23 nm and a net negative charge of -22.7. We evidenced that SeNPs possess considerable antimicrobial activity against three gram-positive, three gram-negative bacteria, and three strains from both Candida sp. and Aspergillus sp. Moreover, SeNPs were able to scavenge ABTS and DPPH radicals in a dose-dependent manner. An association was found between the total phenolic content of Spirulina and SeNPs and their biological activities. Our results indicate that Spirulina and SeNPs with significant antimicrobial and antioxidant activities seem to be successful candidates for safe and reliable medical applications.

Keywords: Antimicrobial; Antioxidant; Bacillus subtilis; Biogenic SeNPs; Green nanotechnology; Spirulina platensis.