Optimization of the biosynthesis of silver nanoparticles using bacterial extracts and their antimicrobial potential

Iván Solís-Sandí; Sara Cordero-Fuentes; Reinaldo Pereira-Reyes; José Roberto Vega-Baudrit; Diego Batista-Menezes; Gabriela Montes de Oca-Vásquez

doi:10.1016/j.btre.2023.e00816

Optimization of the biosynthesis of silver nanoparticles using bacterial extracts and their antimicrobial potential

Biotechnol Rep (Amst). 2023 Oct 29:40:e00816. doi: 10.1016/j.btre.2023.e00816. eCollection 2023 Dec.

Authors

Iván Solís-Sandí¹, Sara Cordero-Fuentes², Reinaldo Pereira-Reyes³, José Roberto Vega-Baudrit^{3

4}, Diego Batista-Menezes³, Gabriela Montes de Oca-Vásquez^{3

5}

Affiliations

¹ School of Biology, Tecnológico de Costa Rica, Campus Central, 159-7050 Cartago, Costa Rica.
² School of Chemistry, Universidad Nacional, Campus Omar Dengo, 86-3000 Heredia, Costa Rica.
³ National Nanotechnology Laboratory, National Center for High Technology, 10109 Pavas, San José, Costa Rica.
⁴ Laboratory of Polymer Science and Technology, School of Chemistry, Universidad Nacional, Campus Omar Dengo, 86-3000 Heredia, Costa Rica.
⁵ Center for Sustainable Development Studies, Universidad Técnica Nacional, 1902-4050, Alajuela, Costa Rica.

Abstract

In the present study, silver nanoparticles (AgNPs) were biosynthesized using the supernatant and the intracellular extract of Cupriavidus necator, Bacillus megaterium, and Bacillus subtilis. The characterization of the AgNPs was carried out using UV-Vis spectroscopy, FTIR, DLS and TEM. Resazurin microtiter-plate assay was used to determine the antimicrobial action of AgNPs against Escherichia coli. UV-Visible spectra showed peaks between 414 and 460 nm. TEM analysis revealed that the synthesized AgNPs showed mostly spherical shapes. DLS results determined sizes from 20.8 to 118.4 nm. The highest antimicrobial activity was obtained with the AgNPs synthesized with supernatant rather than those using the intracellular extract. Therefore, it was determined that the bacterial species, temperature, pH, and type of extract (supernatant or intracellular) influence the biosynthesis. This synthesis thus offers a simple, environmentally friendly, and low-cost method for the production of AgNPs, which can be used as antibacterial agents.

Keywords: Antimicrobial effect; Bacterial extracts; Biosynthesis; Characterization; Silver nanoparticles.