Abstract
Yeast was cultured on mediums containing glucose or a fatty acid ester as carbon sources, and the effects of these carbon sources, and of culture conditions such as temperature, aeration and C/N ratio on the dry weight of the yeast, lipid content and fatty acid composition of the lipid were examined. Where the carbon source was glucose, the concentration of palmitic acid increased with exposure of the yeast to lower temperatures, the concentration of linoleic acid rose with increased aeration, and the concentration of stearic acid rose with a higher C/N ratio.
Where the carbon source was a fatty acid ester, the dry weight of the yeast increased, and the fatty acid composition of yeast lipid varied greatly according to the kind of ester used. For example, when ethyl stearate, butyl stearate or ethyl oleate was used as carbon source, the composition differed greatly ; where butyl stearate was used, the activity of substrate-incorporating enzymes was low ; and where ethyl stearate was used, there was a low hexadecenoic acid content, although this was present in significant quantities when other ethyl esters were used.
