Abstract: In this research, the anti-quorum sensing activity of ethyl maltol was evaluated using the quorum sensing reporter strain Chromobacterium violaceum 026 (CV026). The effect of ethyl maltol on the secretion of signal molecules in Aeromonas salmonioida was detected by gas chromatography-mass spectrometry (GC-MS). The inhibitory effect of ethyl maltol on the quorum sensing and spoilage capacity of Aeromonas salmonida in the presence of exogenous signaling molecules was determined by measuring the biofilm formation ability, extracellular protease activity and swarming and swimming motilities. The results showed that the minimum inhibitory concentration of ethyl maltol against CV026 and Aeromonas salmonioida was 0.1 mg/mL, and ethyl maltol could reduce the violacein-producing ability of CV026 at the sub-minimum inhibitory concentration (sub-MIC). According to GC-MS analysis, ethyl maltol significantly reduced the production of the quorum sensing signal molecule C12-HSL by Aeromonas salmonida. The biofilm formation, extracellular protease activity and swarming and swimming motilities of Aeromonas salmonida were inhibited by 71.2%, 69.1%, 80.4% and 82.1% by 0.08 mg/mL ethyl mathol, respectively, and the inhibitory effect was dose-dependent. Therefore, ethyl maltol has an obvious inhibitory effect on the quorum sensing of Aeromonas salmonida and can be developed as a quorum sensing inhibitor for the preservation of aquatic products.

Key words: ethyl maltol; Aeromonas salmonicida; quorum sensing; inhibitor