TABLE 3.
Determination of growth parameters in acidified LB mediuma
| Initial pH | Final plate count (log[CFU/ml]) |
Final pH |
Lag phase (h) |
Growth rate (1/h) |
Final OD |
|||||
|---|---|---|---|---|---|---|---|---|---|---|
| Without budAB | With budAB | Without budAB | With budAB | Without budAB | With budAB | Without budAB | With budAB | Without budAB | With budAB | |
| 4.00 | 4.0 ± 0.2 A | 3.9 ± 0.3 A | 4.08 ± 0.01 A | 4.08 ± 0.01 A | ||||||
| 4.10 | 2.6 ± 0.3 B | 8.3 ± 0.1 A | 4.29 ± 0.01 B | 5.23 ± 0.33 A | 29.7 ± 3.0 | 0.040 ± 0.007 | 0.813 ± 0.118 | |||
| 4.20 | 6.5 ± 0.2 B | 8.4 ± 0.1 A | 4.39 ± 0.04 B | 5.56 ± 0.03 A | 9.3 ± 0.3 A | 9.2 ± 0.4 A | 0.011 ± 0.002 B | 0.063 ± 0.001 A | 0.378 ± 0.023 B | 0.976 ± 0.006 A |
| 4.30 | 7.2 ± 0.1 B | 8.3 ± 0.1 A | 4.36 ± 0.02 B | 5.73 ± 0.03 A | 6.0 ± 0.3 A | 6.1 ± 0.2 A | 0.018 ± 0.002 B | 0.071 ± 0.001 A | 0.418 ± 0.032 B | 1.008 ± 0.022 A |
| 4.40 | 7.2 ± 0.2 B | 8.4 ± 0.1 A | 4.40 ± 0.01 B | 5.78 ± 0.04 A | 5.3 ± 0.2 A | 5.3 ± 0.3 A | 0.026 ± 0.001 B | 0.077 ± 0.001 A | 0.461 ± 0.022 B | 1.026 ± 0.025 A |
| 4.50 | 7.5 ± 0.1 B | 8.3 ± 0.1 A | 4.42 ± 0.01 B | 5.88 ± 0.05 A | 2.0 ± 0.2 A | 2.1 ± 0.3 A | 0.026 ± 0.004 B | 0.076 ± 0.003 A | 0.483 ± 0.033 B | 1.046 ± 0.016 A |
a
E. coli MG1655 harboring pTrc99A (without budAB) or pTrc99A-Ptrc-budAB (with budAB) was grown in LB (acidified to different initial pH values) containing 0.5% glucose, 1 mM IPTG, and 100 μg/ml ampicillin at 30°C for 72 h. Lag phases, growth rates, and final ODs were determined after fitting of the growth curves using DMFit. Values are means ± standard deviations. Values for each parameter followed by different capital letters in the same row are significantly different (P < 0.05).