EXTRACTION, PARTIAL PURIFICATION, AND CHARACTERIZATION OF AN INHIBITORY COMPOUND DERIVED FROM Candida oleophila

Abstract

Natural extracellular products from the yeasts, Candida oleophila, strain 182, and Saccharomyces cerevisiae, strain 119, were isolated, partially purified, characterized, and tested for bioactivity against fungal growth. The extracellular material from each yeast was isolated by a variety of extraction protocols. The resulting extract was then compared for effectiveness in inhibiting fungal growth by a series of in vitro bioassays, and by one in vivo bioassay. Comparisons were made between yeast species, and against a media blank which had undergone the same extraction protocol. In two in vitro bioassays, the reagents alone were tested. Extracts from the two yeasts were partially purified by low pressure column chromatography and high performance liquid chromatography. Fractions eluted from each yeast were characterized for protein and sugar content. Fractions eluted by low pressure column chromatography were also tested for bioactivity by in vitro bioassay. No significant inhibitory bioactivity was found to be directly related to the extracellular compounds alone. Fungal spore inhibition was associated with some reagents added in the extraction process, or salts eluted in fractions by anion-exchange low pressure column chromatography. Competition, not amensalism, may be he primary mechanism by which these yeasts inhibit fungi.