Characterization by gas chromatography/mass spectrometry of sterols in Saccharomyces cerevisiae during autolysis
1999
Le Fur, Y. | Maume, G. | Feuillat, M. | Maume, B.F.
Yeast autolysis affects membrane stability and induces a release of vacuolar enzymes into the cell cytoplasm. Consecutively, it was important to study the evolution of sterol content in Saccharomyces cerevisiae for a fourteen day period of accelerated autolysis. Unesterified and esterified sterols were analyzed both in the biomass and in the autolysis medium. Ten sterols were identified by gas chromatography/mass spectrometry. A second group of six sterols was separated and partially characterized. Among the first group of 10 sterols, a dehydroergosterol was identified as ergosta-5,7,9(11),22-tetraen-3beta-ol, not yet characterized in S. cerevisiae. Yeast autolysis induced a decrease of esterified sterol content, especially first intermediates in the sequence of the ergosterol biosynthesis, as zymosterol. In contrast, the yeast autolysis resulted in the release of a low quantity of sterols into the medium. At the end of the fourteenth day of autolysis, 0.015% of the total sterol content of the initial biomass was found in the medium.
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