الفهرس 
Antimicrobial EffectOnly 14 pages are availabe for public view
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Abstract
noticed The present investigation was carried out to study the microbiological and chemical characteristics of the essential oils produced by some medicinal plants (clove, thyme, cinnamon, cumin, black cumin, caraway, anise, majorana, pepperment and fennel).The antimicrobial potency of these med. plants was examined studying the effect of aqueous extracts and the effect of different four organic solvents (acetone, chloroform, benzene and petrolium ether).Seven tested microorganisms were used five selected bacterial strains (Staph. aureus, B. cereus, E. coli, Ps. aeruginosa and Salmonella typhimurium) and two selected fungi (Aspergillus flavus and Aspergillus niger).Determination chemical analysis of the used med. plants to estimate the volatile components which give the antimicrobial potency against such microbial food born organisms. ill the used organic solvents showed capability to extract the effective components from tested med. plants but, the petroleum ether extract gave the strongest effect on all tested microorganisms followed by acetone and chloroform. While, the lowest effect by benzene.The obtained results indicated that all of the selected organisms showed different resistance to the plants extracts but, the Staph. aureus and Salmonella typhimurium were more sensitive to the tested plants extracts. It could be observed that the aqueous extract of all the tested med. plants have the strongest effect comparing with organic solvents extract.Clove, thyme and cinnamon extracts gave the strongest effect on the microbial growth than other tested med. plants extract.E. coli is more resistance to thyme aqueous extract than the other tested organisms. On the other side, Salmonella typhimurium was more sensitive to aqueous extract of black cumin. While, E. coli, Ps. aeruginosa and Staph. aureus were more sensitive to the oil of cumin. Oil however Staph. aureus is more resistance to anise aqueous extract.The aqueous extract of majorana had the lowest effect on microbial growth of Staph. aureus and B. cereus while, aqueous and solvents extracts of pepperment and fennel showed variable effect on the growth of tested microorganisms.Acetone, petrolium ether and chloroform extracts showed benzene extract showed the lowest effect on the same microorganisms. Aqueous and solvents extracts of clove, thyme and cinnamon possessed varying antifungal activities against A. flavus and A. niger.All of the tested plant extracts showed cleared antifungal activities against tested fungi.Fungal growth were affected by the addition of plant extracts which reflected on the microbial activity of enzymes production.There is no clear differences between amylase and protease enzymes of tested organisms but, lipase enzyme was generally low compared with the others.The antimicrobial potency of the aqueous extract of (clove and thyme) mixture was examined. It could be observed that this mixture had a strong potent antibacterial efficacy against microorganisms under investigation. The plant essential oil composition of med. plants under investigation were determined. The dominant substances from clove, thyme and cinnamon were eugenol (83.66%), thymol (39.43%) a The plant essential oil composition of med. plants under investigation were determined. The dominant substances from clove, thyme and cinnamon were eugenol (83.66%), thymol (39.43%) and cinnamaldehyde (79.82%) respectively. On the other hand, cis-isoeugenol occurred as a major component in black cumin (31.57%) while, the major components for carawy, cumin, anise and majorana were P. allylanisol (76.15%), cis-isoeugenol (69.75%), anethole (90.28%) and 1.2 propadiene, allene, argon (80.15%) respectively. On the other hand, methyl propenyl trichloro heptane (70.66%) and propadiene, argon, propionic acid (63.79%) were the most prevalent compounds in pepperment and fennel respectively. It appears that there is a relationship between the extent of the inhibitory effect of the tested med. plant oils and the presence of aromatic nucleus containing a polar functional group.