Fig. 2. Genetic requirements for CupB5-mediated alginate overproduction.

(A) Wild-type (WT) or mutant PAO1 strains were transformed with pHERD20 encoding HA-CupB5-H₆, grown on PIA plates with 0.1% L-arabinose for 24 h at 37°C to induce HA-CupB5-H₆ overexpression, and mucoid phenotypes and alginate production were determined. The algD gene encodes an enzyme required for alginate production. The algU, algW, mucP, clpX, and clpP genes are required for induction of algU-dependent alginate production. (B) Alginate production and mucoid phenotypes of different strains were measured after growth for 24 h at 37°C on PIA plates plus 300 μg m⁻¹ carbenecillin and 0.1% L-Ara. In both panels, values are averages ± SEM (n=3).