Table 1.
Comparison of normalized fluorescence of cells carrying the different versions of putative 3-HP-inducible gene expression systems from P. putida KT2440 (Pp) and C. necator H16 (Cn) in the presence or absence of 10 mM 3-HP.
| Switchable system | E. coli MG1655 | C. necator H16 | ||||
|---|---|---|---|---|---|---|
| Fluorescence intensity/OD600 | Induction ratio | Fluorescence intensity/OD600 | Induction ratio | |||
| Uninduced | Induced | Uninduced | Induced | |||
| PpMmsR/PmmsA | 59 ± 3 | 721 ± 24 | 12.3* | 444 ± 80 | 22,857 ± 1808 | 51.5* |
| PpHpdR/PhpdH | 1,259 ± 68 | 29,351 ± 756 | 23.3* | 304 ± 46 | 157,052 ± 8,409 | 516.6* |
| CnAraC/PacaD | 0 ± 0 | 0 ± 0 | 0 | 311 ± 16 | 464 ± 69 | 1.5 |
| CnHpdR/PmmsA1 | 22 ± 6 | 26 ± 5 | 1.2 | 847 ± 27 | 74,839 ± 1,763 | 88.4* |
| PpPmmsA | 193 ± 16 | 243 ± 23 | 1.3 | 44 ± 8 | 42 ± 4 | 1.0 |
| PpPhpdH | 908 ± 60 | 1,077 ± 47 | 1.2 | 42 ± 1 | 40 ± 3 | 1.0 |
Each system is composed of either a putative 3-HP-inducible promoter and its respective transcriptional regulator or a 3-HP-inducible promoter only. The mean values and standard deviations represent the normalized fluorescence of biological triplicates six hours after induction for E. coli MG1655 and C. necator H16. Asterisks indicate statistically significant induction values for p < 0.01 (unpaired t test).