Green Biosynthesis of Silver Nanoparticles from Olive and Walnut-Related Bacteria, Synthesis, Characterization, and Antimicrobial Activity

Many studies have demonstrated the effectiveness of various plant extracts in the synthesis of silver nanoparticles. The phytochemical components of plant extracts contain biodegradable agents necessary for the stabilization and synthesis of nanoparticles. However, extracellular components of microorganisms have been shown to have similar activity in recent years. This study expects nanoparticle synthesis using silver nitrate using bacteria from different plant and soil parts in the Proteobacteria and Actinomycetes families in the endophytic and free form obtained from various sources, determining their antimicrobial properties on other pathogenic microorganisms. Nanoparticules showed a positive effect on antibiotic-resistant human pathogenic bacteria ( Staphylococcus , Escherichia , and Acinetobacter ), two strains of the human pathogenic Candida , and six different plant pathogenic fungi ( Aspergillus , Fusarium , Gaeumannomyces, and Penicillium ) compared to the reference antibiotics and antifungals. The physical forms and dimensions of the nanoparticles were determined by XRD, FTIR, UV–vis, and scanning electron microscopy. We believe that our findings will be the basis for the bacterial nanoparticle production procedures. Graphical Abstract