佛手柑、柠檬和甜橙精油的抗微生物活性

Screening of EOs for antibacterial activity was carried out by the agar diffusion method, which is normally used as a preliminary check and to select among effective EOs. 

通过琼脂扩散法进行抗菌活性筛选，通常用作初步检验，以选择有效的精油。

The EO of orange showed the lowest antibacterial activity compared to bergamot and lemon EOs, with average diameter inhibition of 11.66mm (Table 2). EO of bergamot presented moderate antibacterial activity, with the diameter of the inhibition zone at 16 mm. It is noteworthy that the highest antimicrobial activity was recorded with lemon EO with an average value of 30.33 mm (Figure 1).

与佛手柑和柠檬精油相比，甜橙精油显示出最低的抗菌活性，平均直径抑制区域为11.66mm。佛手柑精油呈现中等的抗菌活性，其抑制区域的直径为16mm。值得注意的是，柠檬精油记录最高的抗菌活性，平均值为30.33毫米。

Figure 1. Antibacterial activity (S.aureus) of the EOs from citrus, using paper disc-diffusion method, expressed by diameter (mm) of inhibition zone (including the disc diameter, 6 mm). 

Indeed, limonene is the major component of orange EO. It appears that orange EO, which contained 77.40% limonene, was less effective as an antimicrobial than bergamot EO, which contained only 2.20% limonene.

事实上，柠檬烯是甜橙精油的主要成分。似乎含有77.40％的柠檬烯的甜橙精油比仅含有2.20％柠檬烯的佛手柑精油的抗微生物效果较差。

Based on these observations, it is clear that limonene had no influence on the antibacterial potential of the EOs. The compounds present in larger proportions may not necessarily be responsible for the antibacterial activity of EOs. 

基于这些观察，很明显，柠檬烯对精油的抗菌效力没有影响。以较大比例存在的化合物可能不一定对精油的抗菌活性负责。

The results of MICs of EOs tested are shown in Table 3. The bergamot EO showed an inhibitory effect on the dilution of 0.40μL/mL (0.04%), and the inhibitory effect of lemon EO was observed until the dilution corresponded to 0.03% (0.25 μL/mL).

精油测试的最低抑制浓度MIC的结果示见表3。佛手柑精油显示抑制活性，稀释度为0.40 μL/ mL（0.04％），观察柠檬精油的抑制作用，直至稀释度达到0.03％（0.25μL/mL）。

Standard reference antibiotic, chloramphenicol (10 μg/disc) was used as positive control in order to test the sensitivity of the tested microorganism.

使用标准参考抗生素氯霉素（10μg/盘）作为阳性对照，以测试被测微生物的灵敏度。