The Induced (Adaptive) Biosynthesis of  -Galactosidase in Staphylococcus aureus

SUMMARY: Staphylococcus aureus strain Duncan readily synthesized the adaptive (inducible) enzyme β-galactosidase in washed suspension when supplied with a mixture of amino acids and an inducer. The amount of enzyme produced was a function of the quantity of amino acids supplied and the rate of synthesis was determined by the concentration of inducer in the system. Galactose was a highly active inducer, lactose a relatively feeble one. Production of the enzyme ensued after a lag period which could be shortened by the addition of glucose or sodium lactate and further shortened by supplying a mixture of purines and pyrimidines to the system. Enzyme formation was strongly inhibited by various antibacterial agents.