Abstract
To investigate the influence of pantothenic acid deficiency on mitochondria, Saccharomyces cerevisiae, a pantothenate requiring strain isolate from a commercial baker's yeast was cultured with a pantothenate sufficient (200μg/liter) and a deficient (10μg/liter) medium. These microorganisms were observed morphologically with the electron microscope and analyzed for the lipid composition. And it was recognized that in pantothenate sufficient cells the existence of mitochondria was clear enough, but in the deficient cells the membrane structure of mitochondria was not proved. However, when pantothenate was sufficiently added to the cells in the deficient medium at the exponential phase the formation of mitochondria was detected after 18 hours as in the sufficient cells.
In the pantothenate deficient cells, the formation of lipids was markedly inhibited, and phospholipid constituted was almost 85% of the total lipid. And the amount of 32P incorporated into the deficient cells was two times that in the sufficient cells, but the ratio of the count of phospholipid-32P relative to the total was somewhat lower than that of the sufficient cells.
In the pantothenate sufficient yeast, the principal fatty acid in total lipid, neutral fat and phospholipid was found to be palmitoleic acid followed by oleic acid regardless of the kind of lipid. In contract, in the deficient cells, oleic acid was the principal component and palmitoleic acid followed it. These results may suggest that (I) pantothenate deficiency affects the membrane formation through the disturbance of lipid metabolism and (II) the organism plays an economical control on the fatty acid synthesis in the deficient condition.
