TABLE 1.
Phenotypic characterization of M. acetivorans C2A transformed with various ileS-carrying plasmids
| Plasmida | Presence of mutation:
|
MICb (μg/ml) | Growth ratec (h) | ||||
|---|---|---|---|---|---|---|---|
| A440V | A482T | G587D | G593D | G594E | |||
| pJK44 | − | − | − | − | − | <35 | NG |
| pPB13 | + | − | − | − | − | 35 | 33.3 (1.1) |
| pPB3 | − | − | − | − | + | 70 | 37.1 (8.0) |
| pPB24 | − | − | − | − | + | 70 | 28.0 (0.8) |
| pPB29 | − | − | − | − | + | 70 | 28.3 (0.3) |
| pPB22 | − | − | + | − | − | 70 | 26.6 (1.0) |
| pPB4 | − | + | − | − | + | 70 | 32.9 (6.5) |
| pPB6 | − | − | − | + | + | 140 | 17.8 (0.9) |
| pPB7 | − | − | − | + | + | 140 | 15.8 (0.8) |
| pPB5 | + | − | − | − | + | 280 | 16.5 (1.1) |
| pPB8 | + | + | − | − | + | 560 | 15.1 (0.9) |
| pPB12 | + | − | − | + | + | 560 | 14.9 (1.8) |
| pPB23 | + | − | − | + | + | 560 | 20.5 (0.6) |
Plasmid pJK44 carries the wild-type ileS gene from M. barkeri Fusaro (Fig. 2). Other plasmids are identical to pJK44, except that each carries the mutations indicated.
MICs were determined as described in Materials and Methods in HS-MA medium plus pseudomonic acid added at concentrations of 0, 35, 70, 140, 280, 560, and 1,120 μg/ml. The MIC for M. acetivorans C2A was determined to be ca. 12 μg/ml in a different experiment (data not shown).
Generation times were determined as described in Materials and Methods in HS-MA medium plus pseudomonic acid (35 μg/ml). The values shown represent six independent determinations. Standard deviations are in parentheses. NG indicates that growth was not observed. Wild-type M. acetivorans C2A grew with a generation time of ca. 6 h in HS-MA medium but did not grow when PA was added to the medium.