Naslov
Lipid Composition of the Whole Cells, Plasma Membrane and Mitochondria of Brewer's Yeast

Autori
Blagović, Branka ; Rupčić, Jasminka ; Mesarić, Marko ; Georgiú, Katica ; Marić, Vladimir

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Biotechnology and Environment / Kniewald, Zlatko - Zagreb : Hrvatsko Društvo za Biotehnologiju, 2001

Skup
Biotechnology and Environment

Mjesto i datum
Zagreb, Hrvatska, 19.02.2001. - 22.02.2001

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
brewer's yeast; ergosterol; squalene; phospholipids; fatty acids

Sažetak
Lipids are essential components of all living cells because they are structural components of biological membranes, serve as energy reserves and second messengers. The lipid fraction of Saccharomyces uvarum, obtained as a by-product of industrial beer production was analysed. The content and the composition of neutral lipids and phospholipids of the whole cells, plasma membrane and mitochondria were determined. The aim of analysis was better evaluation of nutritive and pharmacological properties of the brewer's yeast, which could result in some additional applications and, consequently, in decreased environmental pollution, since it partially ends in the waste waters. Plasma membranes and mitochondria were isolated after enzymatic disruption of the cell wall. The quality of the organellar preparations was checked by SDS-PAGE and Western blotting. Lipids were extracted by Folch method and analysed by standard methods. The total lipid content was relatively low ( 4,4% of dry cell biomass). Total phospholipids accounted for 31% of total lipids, with phosphatidylcholine as the major one. Phospholipide to protein ratio was significantly higher in the plasma membrane than in the mitochondria (78 mg/g and 59 mg/g respectively). Phosphatidylinositol was the main phospholipide class in the composition of plasma membrane (37%), while in the mitochondria it was phosphatidylcholine (26%). In the composition of neutral lipids of the whole cells, squalene was by far the most abundant making up 33% of total lipids. This finding was supported by the results for the plasma membrane and mitochondria, where the low content of ergosterol and markedly high content of squalene were found. Such a low content of ergosterol, resulting in the accumulation of squalene, is the consequence of strongly anaerobic conditions since the essential step in the biosynthesis of ergoseerol is oxygen-requiring. Although brewer's yeast does not belong to so-called lipid yeasts, high squalene content gives reason for additional exploitation of this by-product of beer production.

Izvorni jezik
Engleski

Znanstvena područja
Biologija, Prehrambena tehnologija

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