Biocontrol Efficiency of Medicinal Plants Against Pectobacterium Carotovorum, Ralstonia Solanacearum and Escherichia Coli

ABSTRACT

The spread of antibiotic resistant pathogens is one of the most serious menaces to successful treatment of microbial diseases. Medicinal and aromatic plants are widely used as traditional medicines and constitute a major source of natural organic compounds. In this research essential oils of Coriandrum sativum, Thymus vulgaris, Cuminum cyminum, Rosmarinus officinalis and Eucalyptus globulus were evaluated for their antibacterial activities, against Pectobacterium carotovorum, Ralstonia solanacearum and Escherichia coli. The essential oils were used at different concentrations 0, 0.01, 0.05, 0.1, 0.5, 1, 5, 10, 25, 50, 75 or 100 % (v/v). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by two-fold broth dilution method for the tested pathogens and the zone of inhibition was determined by agar disk diffusion method. Means were compared using Duncan's Multiple Range Test at the 1% level of significance by MSTATC software. Results showed that the most active essential oils against tested bacteria was thyme oil with the inhibition zone of 34.8 mm against R. solanacearum and the MIC of 1 μl/ml while this value was higher than Streptomycin and Erythromycin inhibition used as positive control. Essential oils of Coriandrum sativum, Cuminum cyminum, Rosmarinus officinalis and Eucalyptus globulus were in the next positions. The efficacy of essential oils from E. globulus was insignificant.

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