Investigation of Antibacterial Activity of Essential Oil of Gamma Irradiated Caraway Seeds (Carum carvi L.)

The antibacterial activity of essential oil extracted from gamma irradiated caraway seeds was studied by using of disk diffusion method and Minimal inhibitory concentration and Minimal bactericidal concentration. Caraway seeds were irradiated at the dosages of 0, 10 and 25 kilogray by a 60Co source of Gammacell system 220. The essential oil samples were extracted using Clevenger method and their antibacterial activities were studied by the use of disk diffusion method on four species of bacteria, namely: Escherichia coli (ATCC 25922), Pseudomonas aeroginosa (ATCC 27853), Bacillus subtilis (ATCC 6633) and Staphylococcus aureus (ATCC 29213) on the PCA and MHA culture media. Afterward, the diameters of the inhibition zones were studied. In addition, the antibacterial activity of the essential oil was compared with antibiotics such as ciprofloxacin, chloramphenicol and gentamicin on these bacteria in similar conditions. Minimal inhibitory concentration and Minimal bactericidal concentration of essential oil were also determined on these bacterial suspensions. The results showed that the antibacterial activity of the extracted essential oil from the irradiated caraway seeds. In addition, the Gram positive bacteria of Bacillus subtilis and Staphylococcus aureus were found tohave more sensitivity with respect to the Gram negative Escherichia coli and Pseudomonas aeroginosa. The results also showed that the antibacterial activity of essential oil extracted from the gamma irradiated with 25 kilogry caraway seeds decreased slightly.