<p xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:mml="http://www.w3.org/1998/Math/MathML">The antimicrobial activity of EOs depends on their chemical constituents. Apparently, the antimicrobial activity of the EO analyzed is related to the presence of phenolic compounds (thymol) and terpene hydrocarbons (&#947;-terpinene), respectively [<bold><xref rid="R4" ref-type="bibr">4</xref></bold>,<bold><xref rid="R7" ref-type="bibr">7</xref></bold>,<bold><xref rid="R18" ref-type="bibr">18</xref></bold>]. p-Cymene, the third major element according to percentage, does not show antibacterial efficacy when used alone [<bold><xref rid="R7" ref-type="bibr">7</xref></bold>], synergistic effects being however attributed to it in relation to thymol and &#947;-terpinene, respectively [<bold><xref rid="R19" ref-type="bibr">19</xref></bold>,<bold><xref rid="R20" ref-type="bibr">20</xref></bold>], which might represent another cause of the antimicrobial activity recorded. On the other hand, a number of studies have shown that EOS exhibit stronger antimicrobial activity than that of their major constituents or their mixtures, respectively [<bold><xref rid="R21" ref-type="bibr">21</xref></bold>,<bold><xref rid="R22" ref-type="bibr">22</xref></bold>], which suggests synergistic effects of the minor components, but also the importance of all components in relation to the biological activity of EOs.</p>