TABLE 1.
Synthesis of pyoverdines by strains of P. aeruginosa used in this study
| Strain | Pyoverdine synthesisa | Growth with EDDHAb |
|---|---|---|
| PAO | ++ | + |
| PAO pvdF | − | − |
| PAO pvdF(ctx::pvdF) | ++ | + |
| PAO pvdF(ctx::pvdYII) | ++ | + |
| Pa4 | + | + |
| Pa4 pvdYII::lacZ | − | − |
| Pa4 pvdYII::Zcal | − | NDc |
| Pa4 pvdYII(ctx::pvdF) | − | − |
| Pa4 pvdYII(ctx::pvdYII) | + | + |
a
Pyoverdine synthesis (as indicated by production of a fluorescent yellow-green pigment on Kings B agar and by the presence of a characteristic absorbance spectrum in Kings B broth) was detected as described previously (12, 15). ++, large amounts of pyoverdine were synthesized; +, significant amounts of pyoverdine were synthesized; −, no detectable pyoverdine was synthesized.
b
Bacterial growth was recorded after growth at 37°C on Kings B agar containing the iron-chelating compound ethylenediamine(o-hydroxy)phenylacetic acid (EDDHA) (200 μg ml−1). +, good growth after 24 h of incubation; −, no detectable growth after 24 h of incubation.
c
ND, not determined.