TABLE 1.
Effect of ferric pyrophosphate concentration on L. pneumophila growth on BCYE supplemented with l-cysteine or cystine
| Ferric pyrophosphate concn (μg/ml) | Strain | Growtha with the indicated concn (mM) of:
|
|||||
|---|---|---|---|---|---|---|---|
| Cysteine
|
Cystine
|
||||||
| 2.27 | 1.14 | 0.57 | 1.67 | 0.83 | 0.42 | ||
| 250 | WT | +++ | +++ | − | +++ | + | − |
| CYS-1 | +++ | +++ | +++ | +++ | +++ | ++ | |
| 125 | WT | +++ | +++ | − | +++ | + | − |
| CYS-1 | +++ | +++ | +++ | +++ | +++ | ++ | |
| 62.5 | WT | +++ | +++ | − | +++ | + | − |
| CYS-1 | +++ | +++ | +++ | +++ | +++ | ++ | |
| 6.25 | WT | ++ | ++ | − | ++ | +/− | − |
| CYS-1 | +++ | +++ | +++ | +++ | ++ | + | |
a
The relative growth of bacteria on BCYE agar medium was scored visually as follows: +++, normal growth; ++, slow growth; +, poor growth; +/−, microcolonies; and −, no growth. The score is based on triplicate plating for each condition.