Basis of pyruvate inhibition in Thiobacillus thiooxidans.
Addition of 10(-3)m pyruvic acid to cultures of Thiobacillus thiooxidans, at pH 2.3, results in its rapid intracellular accumulation and in the cessation of sulfur oxidation, CO(2) fixation, and oxygen consumption; at pH 7.0, pyruvate neither inhibits oxygen uptake nor accumulates appreciably intracellularly. Pyruvate does not affect CO(2) fixation in cell-free extracts. The data suggest that the cells of T. thiooxidans are passively permeable to pyruvic acid at low pH. Thus entry of pyruvic acid causes accumulation of pyruvate with a concomitant decrease in intracellular pH.
D002245:Carbon Dioxide / Q000378:metabolism; D002247:Carbon Isotopes; D002474:Cell-Free System; D003124:Colorimetry; D003470:Culture Media; D003864:Depression, Chemical; D006863:Hydrogen-Ion Concentration; D008365:Manometry; D010101:Oxygen Consumption / Q000187:drug effects; D011773:Pyruvates / Q000494:pharmacology*; D013431:Sulfates / Q000032:analysis; D013455:Sulfur / Q000378:metabolism; D013460:Sulfur Isotopes; D013855:Thiobacillus / Q000187:drug effects / Q000378:metabolism*
D002247:Carbon Isotopes; D003470:Culture Media; D011773:Pyruvates; D013431:Sulfates; D013460:Sulfur Isotopes; D002245:Carbon Dioxide; D013455:Sulfur