بررسي خواص ضدباكتريايي نانوذرات اكسيد روي سنتزشده توسط عصارۀ گياه مورد بر گونه‌هاي زانتاموناس در آزمايشگاه و مطالعۀ بيوانفورماتيكي متابوليت‌هاي ثانويۀ اين گياه بر اين باكتري‌ها

Experimental study of anti-bacterial properties of ZnO nanoparticles synthesized by myrtle extract on Xanthomonas spp. an‎d bioinformatics study of its secondary metabolites on these bacteria

زيست فناوري

Nowadays, Xanthomonas species have caused a lot of damage to crops, an‎d the use of chemical pesticides an‎d copper-containing poisons to control them, in addition to environmental hazards, has led to the resistance of many Xanthomonas species to copper. In recent years, the use of zinc oxide nanoparticles has been proposed for pest control due to their antimicrobial properties. These nanoparticles, while toxic to bacteria, can increase plant growth. Green synthesis is a biocompatible an‎d low-cost method for producing these nanoparticles. In this study, aqueous an‎d alcoholic extracts of the plant Myrtus cummunis L. were used to synthesize zinc oxide nanoparticles. Zinc nitrate hexahydrate an‎d zinc acetate dihydrate were used in this synthesis an‎d the resulting nanoparticles were characterized by XRD, FTIR, DLS, an‎d SEM methods. Then, their antimicrobial an‎d antibiofilm effects on two species of Xanthomonas campestris an‎d Xanthomonas axonopodis were investigated using MIC an‎d MBC methods an‎d biofilm inhibition method. The bacterial growth curve in the presence of different concentrations of zinc oxide nanoparticles an‎d myrtle extract was compared with each other. The interaction of secondary metabolites of the plant with the HrcC protein located in the outer membrane of the bacteria was also investigated using molecular docking. The results of this study showed that all synthesized nanoparticles at the concentration of 170 μg/mL could inhibit the growth of two species of Xanthomonas campestris an‎d Xanthomonas axonopodis an‎d inhibit biofilm production by 27.8% to 40.7%. Moreover, zinc oxide nanoparticles synthesized from zinc acetate using the aqueous extract of myrtle, which were spherical in shape with a size of 50 nm, unlike other synthesized nanoparticles had a bactericidal effect at the concentration of 170 μg/mL, an‎d reduced biofilm production in the two tested bacteria by 33.5% to 39.6%. Chemical nanoparticles an‎d nano-alcohol acetate at 341 μg/mL an‎d nano-aqueous nitrate at 682 μg/mL showed bactericidal activity, but nano-alcohol nitrate did not show this activity at the concentrations studied. Moreover, increasing the concentration of inoculated bacteria by 100-fold only affected the MIC of alcoholic extract-acetate nanoparticles, which increased the inhibitory concentration to 341 μg/mL. These results indicate that nanoparticles synthesized from alcoholic extract are weaker than aqueous extract an‎d chemical nanoparticles in terms of antimicrobial activity. The FTIR results showed a difference in the functional groups loaded on the surface of alcoholic nanoparticles compared to aqueous ones. The Bioinformatics results also showed that the compounds in the plant extract could interact with the HrcC protein located in the outer membrane of the bacteria, which is responsible for the secretion of pathogenic proteins of the bacteria. According to the results, the compounds in the aqueous extract of myrtle, after being loaded onto the surface of the nanoparticles, both increase the stability of the nanoparticles an‎d significantly increase the antimicrobial properties. These compounds can interact with bacterial proteins, release zinc nanoparticles an‎d kill the bacteria. As a result, the green synthesis of zinc nanoparticles from zinc acetate salt using the aqueous extract of myrtle, in addition to reducing environmental risks, can increase the antimicrobial properties of the nanoparticles an‎d can be used to control Xanthomonas bacteria.

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