BIOSYNTHESIS OF ZINC OXIDE NANOPARTICLES USING EUCALYPTUS MELLIDORA LEAF EXTRACT AND EVALUATION OF ITS ANTIMICROBIAL EFFECTS

Background and Aim:The biological approaches to synthesis of nanoparticles are better than chemical and physical procedures because of low energy and time expenditure.This method do not require toxic solvents material for environment.Green synthesis of nanoparticles is an eco-friendly method and uses natural solvent.The purpose of this study is to biosynthesis of zinc oxide nanoparticles and to evaluate its antibacterial activityMethods: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 ZnO NPs was confirmed by spectrophotometer (UV-Vis) methods and DLS, Zeta potential ,PDI,SEM and X-ray diffraction.Then antibacterial properties of nanoparticles were evaluated by disk diffusion method and dilution tube MIC (Minimum inhibitory concentration) on standard strains of Staphylococcus aureus PTCC 1431,Bacillus cereus 1015 PTCC and Escherichia coli PTCC 1399,Pseudomonas aeruginosa PTCC 1571 and was compared with the antimicrobial effects of Eucalyptus extract and zinc sulfate.Results: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 ,and a zeta potential of -19.6 mV was recorded,indicating a very good stability of nanoparticles. MIC was measured for Bacillus cereus,Staphylococcus aureus,Pseudomonas aeruginosa and Escherichia coli 0.0078, 0.0019, 0.0019, 0.0019, mg / ml,respectively.Conclusion:results showed biological nanoparticles of ZnO and extract of Eucalyptus as well as zinc sulfate have antimicrobial properties against pathogenic bacteria,but the most antimicrobial effects were observed by ZnO NPs.

Keywords:

Eucalyptus melliodora , Anti-Bacterial Activity , ZnO Nanoparticles