Biosynthetic implications of the sterol content of ergosterol-deficient mutants of yeast

Abstract

Four nystatin-resistant mutants of Saccharomyces cerevisiae, have been shown, by an analysis of the sterols present, to contain metabolic blocks (in norma ergosterol biosynthesis) for C-24 transmethylation, the Δ⁸→Δ⁷-isomerase, the 5,6-dehydrogenase, and the 22,23-dehydrogenase respectively; the previously unknown sterols, cholesta-5,7,22,24-tetraen-3β-ol, ergosta-8,22,24(28)-trien-3β-ol, and ergosta-8,14,24(28)trien-3β-ol were isolated and characterised.