Antimicrobial Activity and Composition of the Essential Oil of Cymbopogon Olivieri (Boiss.) Bor from Iran

The in vitro antimicrobial activity of the essential oil isolated from the aerial parts ofcymbopogon olivieri (boiss.) bor, an aromatic grass of iran was tested against three gramnegativeand four gram-positive bacteria and also three fungi. the results of the bioassaysshowed that the oil has a remarkable antimicrobial activity. bacillus subtilis and candidaalbicans were more sensitive to the oil than other microorganisms with inhibition zones of 20mm and mic values of 3.75 mg/ml and 2.5 mg/ml, respectively. the gram-negative bacteria,pseudomonas aeruginosa was resistant and klebsiella pneumoniae showed less sensitivity tothe oil with mic value of(greater than)15 mg/ml. gc-ms analysis of the oil confirmed the determinationof 40 compounds representing 95.0% of the oil. the main identified constituent was piperitone(48.9%).