Effect of fragarin on the cytoplasmic membrane of the phytopathogen Clavibacter michiganensis

Fragarin, an antibiotic that was isolated and purified from a soluble fract ion of strawberry leaves, may be a new type of preformed antimicrobial comp ound (phytoanticipin). Here, we report that the growth and oxygen consumpti on of the phytopathogenic bacterium Clavibacter michiganensis were rapidly inhibited after the addition of fragarin to cultures. Also, dissipation of the membrane potential and an increase of cell membrane permeability were o bserved in the presence of fragarin. The ability of fragarin to dissipate t he membrane potential was confirmed with the use of small unilamellar lipos omes made with lipids extracted from C. michiganensis. Our results suggest that fragarin is able to act at the membrane level, and that this action is correlated with a decrease in cell viability.