<tocheading>Original Articles</tocheading>

Among antifungal products of natural origin, Pycnoporellus fulgens (Fr) Donk, is active against pathogenic yeasts. Our study was carried out to observe the ultrastructural modifications produced by P. fulgens crude extract on Candida glabrata. Yeasts were submitted to different concentrations (50, 100, 200, 400 micrograms ml-1) for 72 h under constant stirring at 35 degrees C. Transmission electron microscopy revealed that the extract acted on the cell envelope (cell wall and plasmalemma). Cell divisions were also affected by thickening of the septum (50 micrograms ml-1) and a deficiency in the daughter cell wall texture. The extent of the antifungal effect clearly depended on the extract concentration.