Respiratory Development in Saccharomyces cerevisiae Grown at Controlled Oxygen Tension

AUTOR(ES)

Rogers, P. J.

RESUMO

Saccharomyces cerevisiae was grown in batch culture over a wide range of oxygen concentrations, varying from the anaerobic condition to a maximal dissolved oxygen concentration of 3.5 μM. The development of cells was assayed by measuring amounts of the aerobic cytochromes aa3, b, c, and c1, the cellular content of unsaturated fatty acids and ergosterol, and the activity of respiratory enzyme complexes. The half-maximal levels of membrane-bound cytochromes aa3, b, and c1, were reached in cells grown in O2 concentrations around 0.1 μM; this was similar to the oxygen concentration required for half-maximal levels of unsaturated fatty acid and sterol. However, the synthesis of ubiquinone and cytochrome c and the increase in fumarase activity were essentially linear functions of the dissolved oxygen concentration up to 3.5 μM oxygen. The synthesis of the succinate dehydrogenase, succinate cytochrome c reductase, and cytochrome c oxidase complexes showed different responses to changes in O2 concentration in the growth medium. Cyanide-insensitive respiration and P450 cytochrome content were maximal at 0.25 μM oxygen and declined in both more anaerobic and aerobic conditions. Cytochrome c peroxidase and catalase activities in cell-free homogenates were high in all but the most strictly anaerobic cells.

Documentos Relacionados

• Effects of Oxygen Tension and Glucose Repression on Mitochondrial Protein Synthesis in Continuous Cultures of Saccharomyces cerevisiae
• Osmotic Properties of Spheroplasts from Saccharomyces cerevisiae Grown at Different Temperatures
• A Fermentor System for Regulating Oxygen at Low Concentrations in Cultures of Saccharomyces cerevisiae
• Differential Effect of Respiratory Inhibitors on Ergosterol Synthesis by Saccharomyces cerevisiae During Adaptation to Oxygen
• Sporulation Synchrony of Saccharomyces cerevisiae Grown in Various Carbon Sources