Peña Antonio, Sánchez Norma Silvia, Álvarez Helber, Calahorra Martha, Ramírez Jorge
Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, D. F., 04510 México, D. F., México
Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, D. F., 04510 México, D. F., México.
FEMS Yeast Res. 2015 Mar;15(2). doi: 10.1093/femsyr/fou005.
Growth of Saccharomyces cerevisiae stopped by maintaining the pH of the medium in a pH-stat at pH 8.0 or 9.0. Studying its main physiological capacities and comparing cells after incubation at pH 6.0 vs. 8.0 or 9.0, we found that (a) fermentation was moderately decreased by high pH and respiration was similar and sensitive to the addition of an uncoupler, (b) ATP and glucose-6-phosphate levels upon glucose addition increased to similar levels and (c) proton pumping and K(+) transport were also not affected; all this indicating that energy mechanisms were preserved. Growth inhibition at high pH was also not due to a significant lower amino acid transport by the cells or incorporation into proteins. The cell cycle stopped at pH 9.0, probably due to an arrest as a result of adjustments needed by the cells to contend with the changes under these conditions, and microarray experiments showed some relevant changes to this response.
通过在pH自动控制仪中将培养基的pH维持在8.0或9.0，酿酒酵母的生长停止。研究其主要生理能力，并比较在pH 6.0与pH 8.0或9.0下培养后的细胞，我们发现：(a) 高pH会适度降低发酵，呼吸作用相似且对添加解偶联剂敏感；(b) 添加葡萄糖后，ATP和6-磷酸葡萄糖水平升高至相似水平；(c) 质子泵浦和K(+)转运也未受影响；所有这些表明能量机制得以保留。高pH下的生长抑制也不是由于细胞对氨基酸的转运显著降低或氨基酸掺入蛋白质。细胞周期在pH 9.0时停止，可能是由于细胞为应对这些条件下的变化而进行调整导致停滞，微阵列实验显示了对此反应的一些相关变化。
