engleski

The influence of fermentation conditions and recycling on the phospholipid and fatty acid composition of the brewer’s yeast plasma membranes

In this study, phospholipid (PL) and fatty acid (FA) composition of the plasma membrane (PM), as well as the FA composition of the PM phosphatidylcholine (PtdCho) and phosphatidylethanolamine (PtdEtn) in the pure culture (zero generation) and the first three recycled generations of the bottom-fermenting brewer’s yeast have been determined. The PL composition differed markedly among the generations ; in the zero generation phosphatidylinositol (PtdIns) was the main PL, accounting for 27 % of total PLs, followed by phosphatidic acid and PtdCho. In all recycled generations, the main PL was PtdCho with a marked increase in the 1st generation compared to the zero (32 and 20 %, respectively), followed by PtdIns in the 1st and 2nd generations. In the FA composition of the PM, 22 FAs were identified, ranging from C10 to C26. The compositions of the PM FAs, as well as those of PtdCho and PtdEtn were characterised by a high preponderance of C16 acids. Saturated FAs prevailed in the zero generation, while unsaturated prevailed in the 1st and 2nd generation. Although the profiles of FAs in PtdCho and PtdEtn were similar, some marked differences were observed, pointing out to their specific functions in the regulation of membrane properties.

brewer’s yeast ; Saccharomyces cerevisiae ; plasma membrane ; phospholipids ; fatty acids ; recycling

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