engleski

Phospholipid composition of the plasma membrane of baker's and brewer's yeast

Plasma membrane, as the site of primary contact of the cell with its environment, largely determines the survival ability of the cell. It is well known that membrane lipids make a part of an effective adaptation mechanism reflecting the changes in the extracellular space. We have analysed phospholipid composition of the plasma membrane of two industrial yeast strains grown under aerobic (baker's yeast) and anaerobic (brewer's yeast) conditions. Plasma membranes were isolated according to Serrano after mechanical disruption of the cell wall using cell homogenizer and glass beads. The quality of membrane preparations was tested by SDS-PAGE and Western blotting. Lipids were extracted by Folch method. Total phospholipids were quantified spectrophotometrically, as well as individual phospholipid classes after the separation by two-dimensional thin-layer chromatogrqaphy. Phospholipid content of the plasma membranes of two analyzed yeasts was similar: 0, 09 mg / mg proteins for baker's and 0, 08 for brewer's yeast. Qualitatively the phospholipid compositions were similar, but ratios between the main phospholipid classes differed significantly. While in the plasma membrane of baker's yeast the main phospholipid was phosphatidylcholine (36%) followed by phosphatidylinositol (27%), in brewer's yeast the most abundant was phosphatidylinositol making 37% and phosphatidylcholine accounted only for 19%.

nije evidentirano

nije evidentirano