Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Teramo, Italy.
J Appl Microbiol. 2022 Mar;132(3):1866-1876. doi: 10.1111/jam.15376. Epub 2021 Nov 27.
This study aimed to evaluate the effectiveness of selected essential oils (EOs) and hydrolates (Hs) against Listeria monocytogenes biofilms on polystyrene (PS) and stainless steel (SS) surfaces.
Among others, Origanum hirtum EO, Corydothymus capitatus EO and Citrus aurantium H were selected to treat L. monocytogenes biofilms during and after biofilm formation. Sub-minimum inhibitory concentrations (MICs) of C. capitatus EO (0.31 µl/ml) showed the highest inhibiting effect against biofilm formation on PS, while on SS no significant differences between the EOs were observed (43.7%-88.7% inhibition). Overall, the tested biosanitizers showed limited activity as biofilm removal agents. Although generally less effective, C. aurantium H exhibited good biofilm inhibition performance at 62.5 µl/ml, particularly on PS. Confocal laser scanning microscopy proved that sub-MICs of the biosanitizers drastically changed L. monocytogenes biofilm architecture, with bacterial cells elongation in the presence of C. capitatus EO.
Our findings suggest that the tested EOs and H are able to control Listeria biofilms, particularly preventing biofilm formation on both materials. Considering its mild aroma and hydrophilicity, the H exhibited promising perspectives of application.
This study raises the possibility of applying EOs and Hs to control biofilms on different surfaces in the food industry.
本研究旨在评估选定的精油（EOs）和水醇（Hs）对聚苯乙烯（PS）和不锈钢（SS）表面李斯特菌生物膜的有效性。
本研究选择了牛至精油（Origanum hirtum EO）、香桃木精油（Corydothymus capitatus EO）和柑橘属水醇（Citrus aurantium H），在生物膜形成期间和之后处理李斯特菌生物膜。香桃木精油（C. capitatus EO）的亚最小抑菌浓度（MICs，0.31µl/ml）对 PS 上生物膜形成的抑制效果最高，而在 SS 上，EOs 之间没有观察到显著差异（抑制率为 43.7%-88.7%）。总的来说，测试的生物杀菌剂作为生物膜去除剂的活性有限。虽然效果通常较差，但柑橘属水醇在 62.5µl/ml 时表现出良好的生物膜抑制性能，特别是在 PS 上。共聚焦激光扫描显微镜证明，生物杀菌剂的亚 MICs 极大地改变了李斯特菌生物膜的结构，在香桃木精油存在的情况下，细菌细胞伸长。
我们的研究结果表明，测试的 EOs 和 Hs 能够控制李斯特菌生物膜，特别是防止两种材料上的生物膜形成。考虑到其温和的香气和亲水性，H 具有应用的前景。
本研究提出了在食品工业中应用 EOs 和 Hs 控制不同表面生物膜的可能性。
