Effect of the nitrogen source on the fatty acid composition of Saccharomyces cerevisiae

The source and content of nitrogen in the medium are very important in the development of alcoholic fermentations since they both affect the growth of Saccharomyces cerevisiae. Furthermore, the composition of the growth medium and the environmental conditions are known to affect the cell membrane fatty acid composition. The aim of this work was to study how the nitrogen source affects the membrane fatty acid composition. A mixture of amino acids and ammonia delayed the yeast growth when a high content of yeast assimilable nitrogen was present in the media. Cells grown in the mixed nitrogen source had a lower content of total fatty acids with a higher unsaturation degree than cells grown on sole ammonia.