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.