An inhibitor of the adaptability of Pseudomonas fluorescens in a high-salt environment. Phenomenon and mechanism of inhibition

Pseudomonas fluorescens is a spoilage bacterium in food that has the ability to maintain growth and reproduction in high-salt environments. It acts as a defence mechanism through the exclusion of ions and the formation of biofilms. Hence, disrupting this defence mechanism may be a good way to control food spoilage. In this study, a specific flavonoid small molecule baicalin was found, which was able to dismantle the defence mechanism of the bacteria at a lower concentration (400 μM) of treatment. In synergy with salt, baicalin showed a significant inhibitory effect on the growth, c -di-gmp synthetics and biofilm formation of Pseudomonas fluorescens Pf08. Through transcriptomics , we also found that baicalein interfered with bacterial transport and polysaccharide production functions. Through molecular docking and QPCR , we found that baicalin is able to binding with the RpoS protein through hydrogen bonding and thus interfere with its function.