Neutral lipids in the cells and cell envelope fractions of aerobic baker's yeast and anaerobic brewer's yeast

The Effects of Catabolite Derepression on the Accumulation of Steryl Esters and the Activity of -Hydroxymethylglutaryl-CoA Reductase in Saccharomyces cerevisiae

“…Other workers have suggested that the component sterols of the two fractions differ; in particular, zymosterol is predominantly esterified and ergosterol is mainly in the free form (Nurminen et al, 1975;Bailey & Parks, 1975;Hossack et al, 1977). Results presented in Table 1 agree with these general conclusions, and show the response of individual sterols and their esters to derepression.…”

“…This established the relationship between catabolite derepression and sterol accumulation. As sterols in S. cerevisiae may be free or esterified (Johnson et al, 1972;Bailey & Parks, 1975;Nurminen et al, 1975;Hossack et al, 1977), both forms were determined throughout the course of the experiment. The steryl ester component was responsible for the increase in total sterol, whereas the free sterol remained virtually unchanged throughout the experiment (Fig.…”

Effect of Incorporating Additional Oleic Acid Into the Plasma Membrane of Baker's Yeast on the Permeation of Pyruvic Acid

“…The absence of intraccllular membranes was confirmed by deter mining the NADH-oxidase activity as previously described. 8 Plasma membranes were dislodged from the cell walls by shaking about 120 mg dry weight of cell envelopes suspended in 6 ml of buffer or distilled water in a Mickle disintegrator for 30 min. After removing the glass beads by filtration, and the cell walls by centrifugation for 10 min at 3000 o, the mem branes were collected by ccntrifugation for 60 min at 105,000c g.l.c.…”

“…[8][9][10][11] This difference in the lipid composition of the plasma membrane may explain why pyruvic acid penetrates more rapidly into the intact cells of aerobic commercial baker's yeast than into the more anaerobically cultured yeast cells. "-13…”

Quantification of Plasma Membrane Ergosterol of Saccharomyces cerevisiae by Direct-Injection Atmospheric Pressure Chemical Ionization/Tandem Mass Spectrometry

“…Ergosterol is the main sterol present in the plasma membranes of Saccharomyces cerevisiae (1)(2)(3). Due to intense interest in this sterol, several methods are available for the determination of its concentration, e.g., digitonin precipitation/UV spectroscopy (4), highperformance liquid chromatography separation and detection (5,6), and gas chromatography.…”