香茅油对黑曲霉 ATCC 16404 的抗真菌作用。

Antifungal effects of citronella oil against Aspergillus niger ATCC 16404.

机构信息

Research Center of Hydrobiology, Jinan University, Guangzhou 510632, China.

出版信息

Appl Microbiol Biotechnol. 2013 Aug;97(16):7483-92. doi: 10.1007/s00253-012-4460-y. Epub 2012 Oct 19.

Abstract

Essential oils are aromatic oily liquids obtained from some aromatic plant materials. Certain essential oils such as citronella oil contain antifungal activity, but the antifungal effect is still unknown. In this study, we explored the antifungal effect of citronella oil with Aspergillus niger ATCC 16404. The antifungal activity of citronella oil on conidia of A. niger was determined by poisoned food technique, broth dilution method, and disc volatility method. Experimental results indicated that the citronella oil has strong antifungal activity: 0.125 (v/v) and 0.25 % (v/v) citronella oil inhibited the growth of 5 × 10⁵ spore/ml conidia separately for 7 and 28 days while 0.5 % (v/v) citronella oil could completely kill the conidia of 5 × 10⁵ spore/ml. Moreover, the fungicidal kinetic curves revealed that more than 90 % conidia (initial concentration is 5 × 10⁵ spore/ml) were killed in all the treatments with 0.125 to 2 % citronella oil after 24 h. Furthermore, with increase of citronella oil concentration and treatment time, the antifungal activity was increased correspondingly. The 0.5 % (v/v) concentration of citronella oil was a threshold to kill the conidia thoroughly. The surviving conidia treated with 0.5 to 2 % citronella oil decreased by an order of magnitude every day, and no fungus survived after 10 days. With light microscope, scanning electron microscope, and transmission electron microscope, we found that citronella oil could lead to irreversible alteration of the hyphae and conidia. Based on our observation, we hypothesized that the citronella oil destroyed the cell wall of the A. niger hyphae, passed through the cell membrane, penetrated into the cytoplasm, and acted on the main organelles. Subsequently, the hyphae was collapsed and squashed due to large cytoplasm loss, and the organelles were severely destroyed. Similarly, citronella oil could lead to the rupture of hard cell wall and then act on the sporoplasm to kill the conidia. Nevertheless, the citronella oil provides a potential of being a safe and environmentally friendly fungicide in the future.

摘要

香精油是从某些芳香植物材料中提取的芳香油性液体。某些香精油，如香茅油，具有抗真菌活性，但抗真菌作用尚不清楚。在这项研究中，我们研究了香茅油对黑曲霉 ATCC 16404 的抗真菌作用。采用毒力食物技术、肉汤稀释法和圆盘挥发法测定香茅油对黑曲霉分生孢子的抗真菌活性。实验结果表明，香茅油具有很强的抗真菌活性：0.125（v/v）和 0.25%（v/v）香茅油分别抑制 5×10⁵孢子/ml 分生孢子生长 7 和 28 天，而 0.5%（v/v）香茅油可完全杀死 5×10⁵孢子/ml 的分生孢子。此外，杀菌动力学曲线表明，用 0.125 至 2%的香茅油处理后，24 小时内所有处理的分生孢子（初始浓度为 5×10⁵孢子/ml）有超过 90%被杀死。此外，随着香茅油浓度和处理时间的增加，抗真菌活性相应增加。0.5%（v/v）浓度的香茅油是彻底杀死分生孢子的阈值。用 0.5 至 2%的香茅油处理后的存活分生孢子每天减少一个数量级，10 天后没有真菌存活。通过光学显微镜、扫描电子显微镜和透射电子显微镜观察，发现香茅油可导致菌丝和分生孢子不可逆的改变。基于我们的观察，我们假设香茅油破坏了黑曲霉菌丝的细胞壁，穿过细胞膜，渗透到细胞质中，并作用于主要细胞器。随后，由于大量细胞质流失，菌丝坍塌压扁，细胞器严重受损。同样，香茅油可以导致坚硬细胞壁破裂，然后作用于孢子质杀死分生孢子。然而，香茅油在未来有作为一种安全环保的杀菌剂的潜力。