基于群体感应研究丹皮提取物对嗜水气单胞菌致腐性的抑制作用

Inhibitory Effects of Cortex Moutan Extract on Spoilage Abilities of Aeromonas hydrophila Based on Quorum Sensing

首先利用报告菌株紫色杆菌CV026检测模型,确定丹皮提取物具有群体感应抑制活性,然后以从腐败大菱鲆中分离得到的嗜水气单胞菌(Ah-11)为测试对象,以信号分子产生、生物被膜形成、嗜铁素产生、蛋白水解活性以及细菌迁移(群集和泳动)为评价指标,研究丹皮提取物对Ah-11群体感应的抑制作用,并添加外源AHLs分析Ah-11致腐性与其QS系统之间的联系。结果表明,AHLs能够调控Ah-11致腐因子的产生;能够减少Ah-11信号分子的产生,而不影响嗜水气单胞菌的生长速度;能够显著减少其生物被膜的形成量(P<0.05),破坏生物被膜的结构,降低其蛋白水解活性(P<0.05),抑制其迁移能力(群集和泳动),且抑制作用具有质量浓度依赖性。当丹皮提取物质量浓度为1 mg/m L时,对生物被膜、蛋白水解活性、群集现象和泳动的抑制率分别达到65.47%,43.46%,26.94%和51.68%;嗜铁素试验表明丹皮提取物可能含有能够螯合铁的化合物。

In the present investigation, cortex moutan（CM） extract was identified to be a quorum sensing inhibitor by Chromobacterium violaceum CV026 biosensor detecting system. Furthermore, the effect of CM extract on the production of AHLs, siderophore, biofilm formation, proteolytic activity and migration motivity（swarming and swimming） of Aeromonas hydrophila（Ah-11） isolated from corrupt turbot was studied. The addition of exogenous AHLs was used to analyze the relation of spoiled ability and QS system of Ah-11. The results showed that CM extract could reduce the production of AHLs, with no effect on its growth. CM extract could significantly inhibit the formation of the biofilm（P〈0.05）, destroy the structure of biofilm, decrease its proteolytic activity（P〈0.05）, and the inhibitory effect was mass concentration-dependent. When the mass concentration of CM extract was 1 mg/m L, the inhibition rate of biofilm and proteolytic activity were 65.47%, 43.46%, 26.94% and 51.68%, respectively. The assay of siderophore indicated that CM extract may contain some compounds chelating iron.