LIPID COMPOSITION OF SACCHAROMYCES CEREVI- SIAE DEFECTIVE IN MITOCHONDRIA DUE TO PANTOTHENIC ACID DEFICIENCY

Abstract

Lipid composition of Saccharomyces cerevisiae defective in mitochondria and respiratory activity due to pantothenic acid deficiency and its normalization were studied. Quantitatively, the deficient cells contained about one-half of total lipid, one-fifth of fatty acids, one-fourth of ergosterol, and one-half of phospholipids compared with normal cells. Unsaturated fatty acids, such as palmitoleic acid and oleic acid, were decreased in the deficient cells. The composition of fatty acids and phospholipids in mitochondria in both types of cells was the same as in whole cells. Phospholipids, such as phosphatidylethanolamine and glycerol phosphatides, decreased in deficient cells, but the percentage of phosphatidyl-choline increased. Intracellular coenzyme A content was one-fifth of the normal. By the addition of pantothenic acid to the deficient cells, unsaturated fatty acids, especially palmitoleic acid, were synthesized, but other fatty acids were synthesized to only a small extent. The recovery of phospholipids preceded that of fatty acids. Along with the recovery of these lipids, the respiration rate of the deficient cells also reached the normal level.