Comparative Analysis of Antimocrobial Activities of Essential Oils of Some Aromatic Plants against Some Pathogenic Bacteria and Fungi

Abstract

Essential oils are one of the important natural products derived from aromatic plants for their various biological activities. However, the antimicrobial activities vary in potency and usage. Comparative antimicrobial activities of essential oils of lemon grass (Cymbopogon citrtus, Orange (Citrus sinensis) peel Black plun (Vitex doniana), Ginger (Zingber officinale) and Blue gum tree (E. globulus) against four bacterial species (Salmonella typhi, Klebsiella pneumonia, Pseudomonas aeruginesa, and Staphylococcus aureus) and three fungal species (Candida albicans, Aspergillus flavus and Aspergillus niger). The essential oils were extracted by steam distillation and hydrodistillation. Antibacterial and antifungal activities were determined by paper disc diffusion technique and micro-dilution. The results showed all the essential oils exhibited strong antibacterial and antifungal activities against the test organisms with zones of inhibition ranging from 8.12mm to 26.00 mm. In comparison the inhibitory activities of the oils showed Ginger with 26.00mm against Aspergillus niger, while E. globulus has 16.50mm. Vitex doniana and Z. officinale had the lowest value of 10.60mm and 8.12mm against Salmonella tyhi. The minimum inhibitory concentration (MIC) indicated values ranging from; 0.12mg/ml to 0.82mg/ml. While minimum bactericidal (MBC) and minimum fungicidal concentration (MFC) had values from 0.20mg/ml to 0.1.10mg/ml. The result demonstrated that the five essential oils   have high potential antimicrobial activities that can be developed into potent drugs. Further studies are needed to isolate the bioactive constituents and determine their mechanisms of action.