title: Ionic and energetic changes at competence in the naturally transformable bacterium Streptococcus pneumoniae.
abstract: Addition of competence factor extracts to trigger competence in a culture of Streptococcus pneumoniae induced an increase in the intracellular pH and the Na+ content of the bacteria without any change in the K+ pool or in the membrane potential. These ionic shifts were concomitant with a stimulation of glycolysis that resulted in an enhanced ATP pool. Thus, in transforming conditions, at extracellular pH 7.8, competent bacteria presented a particularly high energetic state resulting from an increase in delta pH and in the ATP pool, associated with an enhanced Na+ content. These features are discussed in the context of homeostasis regulation in response to an environmental stimulus.
authors.affiliation: Centre de Recherche de Biochimie et Génétique Cellulaires de CNRS, Toulouse, France.
authors.forename: A
authors.initials: A
authors.lastname: Lopez
authors.forename: C
authors.initials: C
authors.lastname: Clavé
authors.forename: R
authors.initials: R
authors.lastname: Capeyrou
authors.forename: V
authors.initials: V
authors.lastname: Lafontan
authors.forename: M C
authors.initials: MC
authors.lastname: Trombe
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D001565:Benzoates / Q000378:metabolism; D019817:Benzoic Acid; D005947:Glucose / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007773:Lactates / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D013296:Streptococcus pneumoniae / Q000235:genetics / Q000378:metabolism*; D014170:Transformation, Genetic
chemical_list: D001565:Benzoates; D007773:Lactates; D000255:Adenosine Triphosphate; D019817:Benzoic Acid; D012964:Sodium; D005947:Glucose; D011188:Potassium