FIG. 2.

Secreted p-NPPC hydrolase activities of previously described mip mutants and their complemented derivatives. (A) Enzymatic activities in culture supernatants of wild-type strain 130b, the AA108 mip deletion mutant of 130b, the NU201 streptomycin-resistant derivative of 130b, and the NU203 mip insertion mutant of NU201. (B) Enzymatic activities in culture supernatants of 130b, AA108, AA108(pmip), and AA109. The data are the means and standard deviations of triplicate cultures. The differences between the Mip-expressing strains and the mip mutants were significant (P < 0.05, as determined by Student's t test). Similar results were obtained on two other occasions.