GREEN SYNTHESIS OF SILVER NANOPARTICLES USING SAGE AND THEIR ANTIBACTERIAL EFFECT ON GRAM-POSITIVE AND GRAM-NEGATIVE BACTERIA

In this work, we focused on the green synthesis of silver nanoparticles (AgNPs). In the green synthesis, plant extracts are used as reducing agents. AgNPs contain surface-bound biomolecules from the used plant extract. We used an aqueous extract from sage (Salvia officinalis). This plant is known for its high content of secondary metabolites with excellent antibacterial activity. Antibacterial activity of AgNPs prepared by green synthesis was investigated. Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli were selected for testing. Methods such as agar diffusion assay and inhibition of bacterial growth curves were used. Minimum inhibitory concentrations (MICE. coli = 250 μg/mL; MICS. aureus = 50 μg/mL) were determined. The radiuses of inhibition zones were about 1.5 cm in both bacterial strains. AgNPs prepared by this method can play an important role in dealing with the problem of bacterial resistance. Bacteria develop resistance not only to typical antibiotics. Bacterial cells are also able to eliminate the effect of AgNPs. By modifying their surface with antibacterial molecules, resistance can be effectively combatted.