Abstract
The enzyme galactose-1-phosphate uridyl transferase, a member of galactozymase, can not be detected in the mutant W 3094 (Gal-4) cells of Escherichia coli K12. However, it is first detected within 5 minutes after infection with HFT-λ phage under the presence of inducer (galactose), and then the enzyme synthesis continues linearly until about 120 minutes after infection. In this system, therefore, the phenotypic expression appears almost immediately after the introduction of Gal+ determinant.
