Genus Artemisia includes about 200 species widely-spread in all continents. Nine species have been registered in Serbia. It is known that some aromatic plants of this genus are used as a source of aroma, and for their stomachic and cholagogue and as anthelminitic properties and they are officially registered in numerous pharmacopoeias in many countries. A survey of the literature reveals that the antimicrobial properties of A. lobelii [syn. A. camphorata Will.; A. alba Turra] have not been the subject of previous study. As a result we decided to determine the antimicrobial activity of A. lobelii oil.

The antimicrobial activity of A. lobelii oil was tested in vitro using the diffusion discs method with the following microorganisms: Staphyloccocus aureus 6538, Escherichia coli 95, Pseudomonas aeruginosa, Klebsiella pneumoniae. For comparison purposes we also, investigated the antimicrobial activity of camphor in concentrations of 10, 20, 30 mg/ml) because it was the main oil constituents. The oil showed an antimicrobial activity against all examined microorganism. Also, camphor did not show any antimicrobial activity against any examined microorganism in concentration of 10 mg/ml, while at a concentration of 20 mg/ml, it showed a low activity only against Klebsiella pneumonia. The oil at full blooming stage was found to be the most effective against all examined microorganisms, while the oil at post-blooming stage had the least activity. We believe that it was significant that Pseudomonas aeruginosa, which is one of the most resistant microorganisms, was sensitive to A. lobelii oil even in concentration 25 mg/ml. As a result, antimicrobial activity of the oil of A. lobelii reveal that it could have some potential for medical purposes.

Key words: Artemisia lobelii, Asteraceae, essential oil, antimicrobial activity.