title: The characteristics of extracellular protein secretion by Staphylococcus aureus (Wood 46) and their relationship to the regulation of alpha-toxin formation.
abstract: The progress of secretion of alpha-toxin and total extracellular protein by Staphylococcus aureus (Wood 46), grown aerobically at 37 degrees C, in a 3% (s/v) tryptone soya broth medium supplemented with vitamins was followed. Exoprotein was secreted at a high rate by intact bacteria during the exponential phase (to 9 h) and into the post-exponential phase. After 18 h, when exoprotein accounted for 33% of the total protein in the culture, no further exoprotein was secreted although the bacterial density continued to increase at a low rate beyond this time. During the phase of active secretion, alpha-toxin represented a constant proportion of total exoprotein, the differential rate of synthesis of which increased by a factor of four after the end of exponential growth. Concomitant with the increase in the differential rate of exoprotein formation there was a fourfold increase in the intracellular concentration of RNA precursor material.
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D001427:Bacterial Toxins / Q000378:metabolism*; D004269:DNA, Bacterial / Q000096:biosynthesis; D009711:Nucleotides / Q000096:biosynthesis; D012329:RNA, Bacterial / Q000096:biosynthesis; D013211:Staphylococcus aureus / Q000254:growth & development / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D009711:Nucleotides; D012329:RNA, Bacterial