Green synthesis of Zinc Oxide Nanoparticles Using Eucalyptus Mellidora Leaf Extract and Evaluation of its Antimicrobial Effects

Green production of nanoparticles is an environmentally friendly method in which natural solvents are used. Green nanoparticle synthesis methods have priority over chemical and physical methods due to the reduction of cost, time and energy. The purpose of this study was to biosynthesize zinc oxide nanoparticles and evaluate the antibacterial activity of these nanoparticles. In this experimental study, the extract of Eucalyptus melliodora was combined at a ratio of 1: 1 with 0. 1 M zinc sulfate and kept at room temperature for 15 minutes. Synthesis of zinc oxide nanoparticles was confirmed by spectrophotometric methods, mean diameter of nanoparticles meaturement, X-ray diffraction and electron microscopy (SEM). Then, the MIC of zinc oxide nanoparticles was measured on standard strains of Staphylococcus aureus 1431PTCC, Bacillus cereus 1015PTCC, Escherichia coli 1399PTCC and Pseudomonas aeruginosa 1571PTCC.
FINDINGS: The absorption peak of ZnO NPs was observed at of 350 nm. The SEM showed ZnO nanoparticles was spherical shape of size ranging from 30 to 50 nm. The highest MIC was observed for Pseudomonas aeruginosa with 0. 0019 mg / ml and the lowest MIC for Bacillus cereus with 0. 62 mg / ml. Also, in comparison with ZnO nanoparticles, Eucalyptus extract and Zinc sulfate had the most antimicrobial activity for zinc oxide nanoparticles and their MIC had significant difference in the effect on the bacteria tested (p <0. 05). The results of this study showed biological nanoparticles of ZnO and aqueous extract of Eucalyptus as well as zinc sulfate have antimicrobial properties, but the most antimicrobial effects were observed by ZnO NPs