ANTIMICROBIAL ACTION OF PROPOLIS AND SOME OF ITS COMPONENTS - THE EFFECTS ON GROWTH, MEMBRANE-POTENTIAL AND MOTILITY OF BACTERIA

The effect of the natural bee product propolis on the physiology of mi croorganisms was investigated using B. subtilis, E. coli and R. sphaer oides. An ethanolic extract of propolis had a bactericidal effect caus ed by the presence of very active, but labile, ingredients. The exact bactericidal effect of propolis was species dependent: it was effectiv e against gram-positive and some gram-negative bacteria. Propolis and some of its cinnamic and flavonoid components were found to uncouple t he energy tranducing cytoplasmic membrane and to inhibit bacterial mot ility. These effects on the bioenergetic status of the membrane may co ntribute to the antimicrobial action of propolis and its observed syne rgism with selected antibiotics.