The present study aimed to evaluate the anti-quorum sensing (anti-QS) and anti-proteolytic potentials of tarragon essential oil (TEO) and its major compounds against food-associated Pseudomonas spp. The activities were verified by in vitro, in silico and in situ approaches. In this work, methyl eugenol (ME)- and β-phellandrene (β-PH)-rich TEO was investigated. TEO at subMIC increased the percentage of saturated fatty acids in the bacterial membranes (from 7 to 22%) and exhibited anti-quorum sensing via decreasing the efficiency of QS autoinducer synthesis [3-oxo-C12-HSL (from 2.028 μg/mL to <LOD), C4-HSL (from 1.312 μg/mL to <LOD) and PQS (from 0.007625 μg/mL to <LOD)]. ME and β-PH were docked into LasR, RhlR and PqsR proteins, with docking scores comparable to native autoinductors. The subMICs of TEO, ME and β-PH decreased the proteolysis in the examined bacteria by 33, 29, and 21% (in TSB medium) and by 29, 26, and 19% (in fish juice medium), respectively. Almost all genes encoding proteases were downregulated by the applied agents. The ME- and β-PH-rich TEO acts as an anti-QS agent and significantly suppresses the proteolytic activity of food-associated pseudomonads. It might therefore increase the quality of fish-based products, where Pseudomonas spp. predominate.

本研究旨在评估龙蒿精油（TEO）及其主要化合物对与食物相关的假单胞菌（Pseudomonas spp ）的抗群体感应（anti-QS）和抗蛋白水解的潜力。通过体外，计算机和原位方法验证了活性。在这项工作中，研究了富含甲基丁香酚（ME）和β-水芹烯（β-PH）的TEO。subMIC处的TEO增加了细菌膜中饱和脂肪酸的百分比（从7％增加到22％），并通过降低QS自动诱导剂合成的效率[3-oxo-C12-HSL（从2.028μg/ mL到<LOD），C4-HSL（从1.312μg/ mL到<LOD）和PQS（从0.007625μg/ mL到<LOD ）]。ME和β-PH分别与LasR，RhlR和PqsR蛋白对接，其对接得分可与天然自体诱导剂媲美。TEO，ME和β-PH的subMICs分别使被检细菌中的蛋白水解降低了33％，29％和21％（在TSB培养基中）和29％，26％和19％（在鱼汁培养基中）。几乎所有编码蛋白酶的基因都被所施加的试剂下调。富含ME和β-PH的TEO充当抗QS剂，并显着抑制与食物相关的假单胞菌的蛋白水解活性。因此，它可能会提高假单胞菌（Pseudomonas spp）鱼类产品的质量。占主导地位。