Antibacterial Efficacy of Selected Essential Oils against Bacillus Megaterium and their Application in Food Preservation

Abstract

Antibacterial effect of ten different essential oils like Clove oil (Syzygium aromaticum), Lemongrass oil (Cymbopogon), Lemon oil (Citrus limonum), Peppermint oil (Mentha piperita), Tea tree oil (Melaleuca alternifolia), Eucalyptus oil (Eucalyptus globulus), Orange oil (Citrus sinensis), Basil oil (Ocimum basilicum), Rosemary oil (Rosmarinus officinalis) and Cinnamon oil (Cinnamomum verum) were studied against the food spoilage bacteria Bacillus megaterium for its application as food preservatives. The oils were tested at the concentrations of 50, 100, 150, 200, 250, 300, 350, 400, 450 and 500 mg/mL. Essential oil with potent antibacterial efficacy was determined individually using agar well diffusion method. Results revealed that among the tested essential oils clove and cinnamon oil exhibit high antibacterial effect. Synergy test was further studied in order to determine the combined efficacy of clove and cinnamon oil. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were also observed.  MIC was found to be as 15.625 and 62.5 mg/mL for clove and cinnamon oil. Similarly MBC were recorded as 31.25 and 62.5 mg/mL.