TABLE 2.

Phenotypic characterization of strain PAO1 and derivatives

Strain (genotype)Concn of:Elastase activityc (A495)Amt of rhamnolipidsd (μg/109 bacteria)HCN concne (nmol/109 bacteria)Growth on adenosinef
Pyocyanina (μg/ml)OdDHLb (μM)BHLb (μM)
PAO14.7 ± 0.60.22 ± 0.063.9 ± 0.20.9 ± 0.27.5 ± 2.22.90 ± 0.30+++
PAO1-J (lasR)20.7 ± 1.1<0.050.2 ± 0.10.1 ± 0.1<1.00.63 ± 0.15+
PAO1-D (lasR)20.6 ± 2.8<0.05<0.10.1 ± 0.0<1.00.43 ± 0.06+
PAO6395 (ΔlasR)15.9 ± 3.4<0.050.1 ± 0.10.1 ± 0.0<1.00.40 ± 0.00+
  • a Pyocyanin was quantified in triplicate cultures grown for 48 h as previously described (46).

  • b OdDHL and BHL concentrations were quantified by thin-layer chromatography, using Agrobacterium tumefaciens NTL4/pZLR4 and Chromobacterium violaceum CV026 as indicators, as previously described (18). Assays were done three times.

  • c Elastase activity was estimated for P. aeruginosa strains grown in triplicate NYB cultures (7, 33). Arbitrary A495 units are used.

  • d Rhamnolipids were quantified (19) for P. aeruginosa strains grown in triplicate NYB cultures.

  • e Concentrations of HCN were determined in triplicate for strains grown under semianaerobic conditions (19).

  • f Growth on OS medium with adenosine as the only C source was scored after 2 days. +++, good growth of single colonies; +, faint growth in primary streak.