TABLE 2.
Biological evaluation of the two essential oils expressed in the inhibition zone (mm).
| Sample code | Bacterium and inhibition zone (mm) a | ||||
|---|---|---|---|---|---|
| Gram-positive bacteria strains | Gram-negative bacteria strains | ||||
| Staphylococcus aureus (ATCC 6538) | Staphylococcus aureus (ATCC 29213) | Staphylococcus epidermidis (ATCC 12228) | Salmonella typhimurium (CMCC 50115) | Escherichia coli (CMCC 44102) | |
| Perfume lemon essential oil (2.56 mg) | 9.87 ± 1.15 | 8.57 ± 0.61 | 9.10 ± 0.78 | ＜6 b | ＜6 |
| Perfume lemon essential oil (100%) c | 10.37 ± 0.67 | 10.20 ± 0.52 | 10.37 ± 0.15 | ＜6 | ＜6 |
| Perfume lemon leaves essential oil (2.56 mg) | 8.97 ± 1.10 | 7.27 ± 0.06 | 7.53 ± 0.61 | ＜6 | ＜6 |
| Perfume lemon leaves essential oil (100%) c | 8.20 ± 0.26 | 7.37 ± 0.12 | 8.23 ± 0.31 | ＜6 | ＜6 |
| (R)-(+)-limonene (2.56 mg) | ND ＃ | ND | ND | ND | ND |
| (R)-(+)-limonene (100%) c | 6.77 ± 0.23 | 6.70 ± 0.50 | 7.13 ± 0.25 | 11.67 ± 0.32 | 7.93 ± 0.35 |
| Citronellal (2.56 mg) | ND | ND | 7.70 ± 0.10 | ND | ND |
| Citronellal (100%) c | ND | ND | 8.60 ± 0.26 | ND | ND |
| Gatifloxacin d | 19.12 ± 0.73 | 17.13 ± 0.64 | 18.67 ± 0.25 | 20.92 ± 0.72 | 20.78 ± 1.06 |
a
Results are expressed as the diameter of inhibition zone (mm), values represent the means of three independent replicates ±SD.
b
＜6, no obvious inhibition zone was detected.
c
Pure perfume lemon and its leaf essential oil with no dilution.
#
ND, not detected.
d
Gatifloxacin was used as a positive control, the dosage of gatifloxacin used in the inhibition zone assay is 1 nmol.