Table 2.
The inhibitory diameters (mm) of PGEO at three developmental stages against bacterial strains.
| Microorganisms/Gram (+ or −) | P. graveolens EOs | Chloramphenicol (30 µg) | ||
|---|---|---|---|---|
| Vegetative Stage | Beginning Flowering Stage | Full Flowering Stage | ||
| Escherchia coli ATCC 25922 (−) | 11.00 ± 0.17 | 12.47 ± 0.06 | 13.43 ± 0.21 | 22.47 ± 0.21 |
| Proteus mirabilis ATCC 25933 (−) | 11.03 ± 0.11 | 12.73 ± 0.15 | 14.57 ± 0.21 | 21.27 ± 0.21 |
| Salmonella Typhimurium ATCC700408 (−) | 8.27 ± 0.11 | 9.93 ± 0.15 | 11.10 ± 0.20 | 13.17 ± 0.25 |
| Bacillus subtilis ATCC 6633 (+) | 14.13 ± 0.11 | 15.23 ± 0.15 | 16.17 ± 0.15 | 15.87 ± 0.21 |
| Staphylococus aureus ATCC 29213 (+) | 14.97 ± 0.15 | 16.10 ± 0.20 | 16. 53 ± 0.15 | 26. 53 ± 0.30 |
| Listeria monocytogenes ATCC 13932 (+) | 15.23 ± 0.15 | 16.83 ± 0.25 | 17.30 ± 0.17 | 29.07 ± 0.58 |
Zones of inhibition included the 6 mm diameter well, at a concentration of 50 μL of oil/well. Diameters in mm. P. graveolens: Pelargonium graveolens; EOs: essential oils; −: Gram-negative bacteria; +: Gram-positive bacteria.