title: Effects of high medium pH on growth, metabolism and transport in Saccharomyces cerevisiae.
abstract: 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.
authors: 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 apd@ifc.unam.mx.
authors: Antonio
authors: A
authors: Peña
authors: 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.
authors: Norma Silvia
authors: NS
authors: Sánchez
authors: 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.
authors: Helber
authors: H
authors: Álvarez
authors: 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.
authors: Martha
authors: M
authors: Calahorra
authors: 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.
authors: Jorge
authors: J
authors: Ramírez
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis; D001692:Biological Transport / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D003470:Culture Media / Q000737:chemistry*; D005285:Fermentation; D019298:Glucose-6-Phosphate / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*
chemical_list: D003470:Culture Media; D019298:Glucose-6-Phosphate; D000255:Adenosine Triphosphate
keywords: Saccharomyces cerevisiae; metabolism and transport; pH and growth; yeast