Comparison of the patterns of increased in alpha-toxin and total extracellular protein by Staphylococcus aureus (Wood 46) grown in media supporting widely differing growth characteristics.

A comparison has been made of total exoprotein formation by Staphylococcus aureus (Wood 46) in a tryptone soya broth (TSB) medium and a casein hydrolysate-yeast extract-containing (CCY) medium in which exponential growth occurred with doubling times of 3.0 and 1.3 h, respectively. It was found that the differential rate of exoprotein formation was biphasic in each case, increasing after the cessation of exponential growth by a factor of 4 in TSB and 7 in CCY medium. Although this relative change was greater in CCY medium, the maximum value of the differential rate was less than 40% of that achieved in TSB medium. It was further shown that throughout the growth cycle, and in both cultures, alpha-toxin accounted for the same proportion of total extracellular protein.