The biological preparation of nanoparticles from plant extract and investigation of their antibacterial activities on pathogenic bacteria isolated from pathogenic sources

Green synthesis is known as the process of combining nanoparticles using plants or their metabolites and focuses on environmentally friendly applications. In these green strategies, plant metabolites and natural substances are used to facilitate the formation of nanoparticles, and they may have applications in the pharmaceutical industry and other fields. Allium plants are known for their interesting biological properties and as producers of abundant secondary metabolites. In this thesis, we explained the basic green synthesis techniques with a focus on metal oxide (MgO) nanoparticles. MgO nanoparticles were extracted using the leaves of the leek plant. In the microscopic characterization, the average grain size of MgO NPs was determined as 44.34 nm and their shape was found to be cylindrical. Trials were conducted to determine the antibacterial effects of MgO nanoparticles at different concentrations (100, 50 and 25 µg/ml) on Klebseiella pneumoniae gram (-) bacteria. The highest MgO nanoparticle effect was obtained at a concentration of 100 µg/ml and the inhibition zone diameter was measured as 17 mm. As the MgO nanoparticle concentration decreased (25 µg/mL), the inhibition zone diameter (13.56 mm) also decreased. In addition, when MgO nanoparticles were examined for antibacterial activity against a gram-negative bacteria, Klebsiella pneumoniae, they were shown to be effective at minimum inhibitory concentration (MIC). The antibacterial effect of MgO nanoparticles was the highest at minimum inhibition concentrations (0.8 μg/ml) and the inhibition zone diameter was measured as 36 mm. When examined in terms of antioxidants, green synthesized MgO nanoparticles were found to have antioxidant properties and the highest antioxidant activity (88.7%) was obtained at the highest MgO nanoparticle concentration (100 g/mL). The antibacterial effects of green synthesized MgO nanoparticles from leek leaf extract were stronger when compared to antibiotics.