Effects of phosphatidylcholine or ergosteryl oleate on physiological properties of Saccharomyces sake.

Abstract

Chromatographically homogeneous phosphatidylcholine identified by thin-layer chromatog-raphy on silica gel G was isolated from mycelia of Aspergillus oryzae or egg yolk by a combination of alumina and silicic acid column chromatography. Although the 2-position in both Asp. oryzae- and egg yolk-phosphatidylcholine was occupied nearly exclusively by unsaturated fatty acids, significant proportions of unsaturated fatty acids were also found in the 1-position of Asp. oryzae-phosphatidylcholine. In nitrogen gas-sparging anaerobic culture of Saccharomyces sake Kyokai No. 7, supplementing the basal synthetic medium with phosphatidylcholine enhanced the yeast growth and fermentative activity, whereas adding ergosteryl oleate enhanced alcohol-endurability. Supplementation with both phosphatidylcholine and ergosteryl oleate promoted the yeast growth, fermentative activity and alcohol-endurability of cells.