Ionic and energetic changes at competence in the naturally transformable bacterium Streptococcus pneumoniae.
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.
Lopez
A
A
Centre de Recherche de Biochimie et Génétique Cellulaires de CNRS, Toulouse, France.
Clavé
C
C
Capeyrou
R
R
Lafontan
V
V
Trombe
M C
MC
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
D001565:Benzoates; D007773:Lactates; D000255:Adenosine Triphosphate; D019817:Benzoic Acid; D012964:Sodium; D005947:Glucose; D011188:Potassium