title: Modification of Saccharomyces cerevisiae thermotolerance following rapid exposure to acid stress.
abstract: Thermotolerance was induced in cells of Saccharomyces cerevisiae YPH499 pre-exposed, during 10 min and in the presence of glucose, to a mild acid-stress with HCl at pH 3.5. Thermotolerance was not induced in cells exposed to a severe acid stress by 50 mM acetic acid at pH 3.5, or HCl at pH 2.5 or pH 2.0. Yeast cells pre-incubated under glucose starvation were found to be more tolerant to a lethal heat stress than cells pre-incubated in glucose-supplemented media, despite the pH value of the media (range 2.0-6.5) and the type of acidulant used (HCl or acetic acid). Moreover, the high thermotolerance exhibited by cells pre-incubated at pH 6.5 for 10 min under glucose starvation was not significantly modified by the acidification of the pre-incubation medium. Results are discussed based on the effect that glucose and a mild or severe acid stress have on plasma membrane H+-ATPase activity and on cytosolic pH values, estimated in a previous work.
authors.affiliation: Centro de Engenharia Biológica e Química, Instituto Superior Técnico, Lisboa, Portugal.
authors.forename: V
authors.initials: V
authors.lastname: Carmelo
authors.forename: R
authors.initials: R
authors.lastname: Santos
authors.forename: C A
authors.initials: CA
authors.lastname: Viegas
authors.forename: I
authors.initials: I
authors.lastname: Sá-Correia
mesh_terms: D019342:Acetic Acid / Q000737:chemistry*; D015169:Colony Count, Microbial; D005947:Glucose / Q000378:metabolism; D006358:Hot Temperature; D006851:Hydrochloric Acid / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*
chemical_list: D005947:Glucose; D019342:Acetic Acid; D006851:Hydrochloric Acid