Table 1.
Growth of Escherichia coli strains in presence of olive phenolics; tyrosol, hydroxytyrosol, DHPG, and oleuropein.
| Presence/absence of inhibitors | Growth on limiting glucosea (%) | Growth on succinateb (%) |
|---|---|---|
| WTc | 100 | 100 |
| Nulld | 48±3 | 0 |
| αR283D | 54±1 | 48±3 |
| αE284R | 63±3 | 59±2 |
| βV265Q | 58±2 | 51±3 |
| γT273A | 54±4 | 47±4 |
| WT + Tyrosol | 1±1 | 0 |
| Null + Tyrosol | 3±1 | 0 |
| αR283D + Tyrosol | 24±4 | 19±4 |
| αE284R + Tyrosol | 3±2 | 6±2 |
| βV265Q + Tyrosol | 3±2 | 5±2 |
| γT273A + Tyrosol | 2±2 | 2±2 |
| WT + Hydroxytyrosol | 23±1 | 20±3 |
| Null + Hydroxytyrosol | 24±2 | 0 |
| αR283D + Hydroxytyrosol | 38±8 | 30±2 |
| αE284R + Hydroxytyrosol | 26±5 | 29±2 |
| βV265Q + Hydroxytyrosol | 8±3 | 11±3 |
| γT273A + Hydroxytyrosol | 5±2 | 6±2 |
| WT + DHPG | 46±4 | 39±2 |
| Null + DHPG | 33±3 | 35±3 |
| αR283D + DHPG | 60±5 | 46±4 |
| αE284R + DHPG | 61±3 | 53±3 |
| βV265Q + DHPG | 38±4 | 42±2 |
| γT273A + DHPG | 6±3 | 7±2 |
| WT + Oleuropein | 24±2 | 16±5 |
| Null + Oleuropein | 10±2 | 0 |
| αR283D + Oleuropein | 9±1 | 11±2 |
| αE284R + Oleuropein | 21±3 | 11±3 |
| βV265Q + Oleuropein | 15±3 | 18±3 |
| γT273A + Oleuropein | 7±3 | 5±2 |
Growth yield on limiting glucose (fermentable carbon source) was measured as OD595 with hourly reading for 24 hours at 37 °C in AccuSkan Go Plate Reader.
Growth on succinate medium (non-fermentable carbon source) was measured as OD595 with hourly reading for 36 hours at 37 °C in AccuSkan Go Plate Reader.
Wild-type (pBWU13.4/DK8) contains UNC+ gene encoding ATP synthase
Null, (pUC118/DK8) is UNC− gene encoding ATP synthase is removed.
The absolute wild-type OD values were used as 100% bench mark to calculate relative OD values for null and mutant. Data points are average of at least three sample assays.
Abbreviations: ATP, adenosine triphosphate; OD, optical density; WT, wild-type.