Biossíntese de nanopartículas de prata utilizando extratos de cianobactérias (Oscillatoriales) do litoral da Bahia e avaliação da atividade antimicrobiana

Abstract

The biosynthesis of silver nanoparticles (AgNPs) mediated by cyanobacteria is a green synthesis method characterized by its low environmental impact compared to conventional chemical processes. In this study, we performed the biosynthesis of AgNPs using the aqueous extract of the Brazilian marine filamentous cyanobacterium Affixifilum granulosum. The nanoparticles were characterized using transmission electron microscopy, energy-dispersive X-ray spectroscopy, dynamic light scattering spectroscopy, and Fourier-transform infrared spectroscopy. We demonstrated their efficacy in inhibiting microbial growth, including Gram-positive bacteria (Bacillus cereus, B. subtilis, and Staphylococcus aureus), Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa), and fungi (Candida albicans and C. glabrata). Additionally, we found that the AgNPs are biocompatible in cytotoxicity assays, maintaining the viability of fibroblast and macrophage cells. These results highlight the potential of AgNPs as antibacterial agents with low cytotoxicity, indicating their promising application in antimicrobial therapy, alongside their eco-friendly synthesis from a Brazilian marine resource.