FIG 4.

Swarming ability and total RL and/or Psl production of RL-deficient mutants and psl and pel mutant strains. (A) Swarming pattern, corresponding swarming zones, Psl levels, and total RL production of PAO1 and the PAO1 isogenic rhlR, rhlAB, pslA, and galU mutants. (B) Swarming and RL production of MJK8, the isogenic psl and/or pel mutant, and native Psl-negative strain PA14. The mean swarming zone diameter and total RL production are presented under each corresponding image. The RL extracts were normalized to the level of PAO1 (214 mg/liter). Psl was detected by immunoblotting with Psl antiserum. ++++, Psl level 4-fold that of PAO1; −, Psl negative; 0, no swarming zone; ND, not determined.