Alterations in Phosphatidylcholine and Phosphatidylethanolamine Content During Fermentative Metabolism in Saccharomyces cerevisiae Brewer’s Yeast
Autor: | Čanadi-Jurešić, Gordana, Blagović, Branka, Rupčić, Jasminka |
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Jazyk: | chorvatština |
Rok vydání: | 2009 |
Předmět: |
Saccharomyces cerevisiae
phospholipids phosphatidylcholine phosphatidylethanolamine fatty acids stress tolerance fosfolipidi fosfatidilkolin fosfatidiletanolamin masne kiseline otpornost na stres food and beverages BIOMEDICINA I ZDRAVSTVO. Temeljne medicinske znanosti. Medicinska biokemija BIOMEDICINE AND HEALTHCARE. Basic Medical Sciences. Medical Biochemistry lipids (amino acids peptides and proteins) |
Zdroj: | Food Technology and Biotechnology Volume 47 Issue 3 |
ISSN: | 1330-9862 1334-2606 |
Popis: | During beer production and serial recycling, brewer’s yeasts are exposed to various stress factors that, overpowering the cellular defence mechanisms, can impair yeast growth and fermentation performance. It is well known that yeast cells acclimatize to stress conditions in part by changing the lipid composition of their membranes. The main focus of this study is the effect of stressful fermentation conditions on two phospholipid species, phosphatidylcholine (PtdCho) and phosphatidylethanolamine (PtdEtn), in Saccharomyces cerevisiae bottom-fermenting brewer’s yeast. For this purpose the content and fatty acid profile of these major classes of phospholipids have been compared, as well as their ratio in the whole cells of the starter culture, non-stressed yeast population, and the first three recycled yeast generations. The stressed yeast generations showed an increased mass fraction of PtdCho and a decreased mass fraction of PtdEtn, which led to an increased PtdCho/PtdEtn ratio in the recycled cells as compared to the non-stressed yeast culture. The most pronounced variation of PtdCho/PtdEtn ratio was found in the second yeast generation, yielding a 78 % increase with respect to the starter culture. Variations in the content of both, PtdCho and PtdEtn, were accompanied by a higher mass fraction of unsaturated fatty acids in both phospholipid species (palmitoleic acid in PtdCho, and palmitoleic and oleic in PtdEtn) and by the increased ratio of C16/C18 acids in PtdCho. The results suggest that both phospholipid species, including their fatty acids, are highly involved in the adaptation of brewer’s yeast to stressful fermentation conditions. Tijekom proizvodnje piva pivski je kvasac izložen nepovoljnim utjecajima. Poznato je da se stanice kvasca prilagođavaju uvjetima okoliša djelomično mijenjajući sastav membranskih lipida. Svrha je ovoga rada proučiti utjecaj nepovoljnih uvjeta tijekom fermentacije na dvije vrste fosfolipida, fosfatidilkolin (PtdCho) i fosfatidiletanolamin (PtdEtn) u pivskom kvascu donjeg vrenja vrste Saccharomyces cerevisiae. U tu je svrhu analiziran i uspoređen njihov udjel i masno-kiselinski sastav u cijelim stanicama starter-kulture, koja nije podvrgnuta nepovoljnim uvjetima, i u prve tri reciklirane generacije kvasca. Reciklirane generacije imale su, u usporedbi sa starter-kulturom, povećani maseni udjel PtdCho i smanjeni udjel PtdEtn, što je rezultiralo većim omjerom PtdCho/PtdEtn. Najveća promjena omjera PtdCho/PtdEtn utvrđena je u drugoj recikliranoj generaciji u kojoj je iznosio 78 % više nego u starter-kulturi. Promjene udjela PtdCho i PtdEtn bile su popraćene povećanim udjelom nezasićenih masnih kiselina u obje vrste (palmitoleinske kiseline u PtdCho, te palmitoleinske i oleinske u PtdEtn), a i većim omjerom C16/C18 kiselina u PtdCho. Dobiveni rezultati upućuju na važnost obje fosfolipidne vrste, uključujući njihove masne kiseline u prilagodbi pivskoga kvasca na nepovoljne uvjete fermentacije. |
Databáze: | OpenAIRE |
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