基于群体感应研究苦丁茶多酚对荧光假单胞菌腐败特性的抑制作用

为探究苦丁茶多酚对分离自卵形鲳鲹的腐败菌荧光假单胞菌（Pseudomonas fluorescens）的抑制作用，本文以报告菌株紫色杆菌(Chromobacterium violaceum) CV026 为检测模型，测定了苦丁茶多酚对细菌的群体感应抑制活性，以胞外酶活性、生物被膜形成量及形态、群集与泳动性为指标，测定了苦丁茶多酚对荧光假单胞菌腐败特性的抑制作用。结果表明:苦丁茶多酚对CV026、荧光假单胞菌的最小抑菌浓度分别为2.1、3.0 mg/mL；在亚抑菌浓度下，苦丁茶多酚可以显著降低紫色杆菌CV026 紫色菌素的产生量（P<0.05）；当浓度为2.0 mg/mL 时，对紫色菌素的抑制率达68.89%，且不影响CV026 菌株的生长；苦丁茶多酚能有效抑制荧光假单胞菌胞外酶活性、生物被膜形成、群集与泳动能力等相关腐败特性，其抑制作用呈剂量依赖性，苦丁茶多酚浓度为2.0 mg/mL时，对蛋白酶、脂肪酶活性、生物被膜形成、群集和泳动能力的抑制率分别达到80.68%、53.50%、44.90%、79.56%和90.12%；苦丁茶多酚具有较好的群体感应抑制活性，可以为新型天然群体感应抑制剂研发提供参考。

Inhibition of Kuding Tea Polyphenols against the Spoilage Characteristics of Pseudomonas fluorescens Based on Quorum Sensing

In order to investigate the inhibitory effects of Kuding tea polyphenols on spoilage bacteria of Pseudomonas fluorescens from Trachinotus ovatus, Chromobacterium violaceum CV026 strain was used as a test model, investigated the effect of Kuding tea polyphenols on quorum sensing and spoilage capacity of P.luorescens. Taking extracellular enzyme activity, the amount and morphology of biofilm formation, clustering and motility as evaluation index, the inhibition effects of Kuding tea polyphenols on spoilage characteristics of Pseudomonas fluorescens were tested. The results showed that the minimum inhibitory concentration (MIC) of Kuding tea polyphenols against CV026 and P. fluorescenswas 2.1 and 3.0 mg/mL, and that Kuding tea polyphenols could significantly reduce the production of violacein in strain CV026 at sub-minimum inhibitory concentrations. When the concentration was 2.0 mg/mL, the inhibition ratio to violacein was 68.89%, while not affecting the growth of CV026 (P<0.05). Kuding tea polyphenols could effectively inhibit spoilage characteristics of Pseudomonas fluorescensas reflected by extracellular enzyme activity of Pseudomonas fluorescens, biofilm formation, swarming and swimming motility, and this effect was positively correlated with its concentration. When the mass concentration of Kuding tea polyphenols extract was 2.0 mg/mL, the inhibition rate of protease, lipase activity, formation of biofilm and the abilities of swarming and swimming motility were 80.68%, 53.50%, 44.90%, 79.56% and 90.12%. Kuding tea polyphenols has very good quorum sensing inhibitory activity, and can provide a reference to the research and development of new quorum sensing inhibitors.