Transcriptome Analysis Reveals the Molecular Mechanism of Pseudomonas with Different Adhesion Abilities on Tilapia Decay

This study aimed to investigate the molecular mechanism of <i>Pseudomonas</i> with varying adhesion capabilities to <i>Tilapia</i>'s intestinal mucus influence the spoilage potential of <i>Tilapia</i>. Sodium chloride(NaCl) was used as an environmental factor to regulate <i>Pseudomonas</i>' adhesion ability. After being exposed to 3.5% NaCl stress, the PS01 strain with low adhesion showed an enhancement in adhesion ability, while the LP-3 strain with high adhesion exhibited a decrease. Correspondingly, the expression of critical adhesion genes, such as <i>flgC</i>, <i>fliC</i>, and <i>cheB</i>, was found to be altered. LP-3, with high adhesion ability, was observed to promote a relative increase in <i>Nocardioides</i> and <i>Cloacibacterium</i> in fish intestines. This led to the production of more volatile compounds, including 2-octen-1-ol Z, 2,3-Octanedione, and Eicosane, thus deepening the spoilage of tilapia. LP-3, with reduced adhesion ability after NaCl regulation, showed a diminished capacity to cause fish spoilage. Transcriptomics analysis was used to examine two <i>Pseudomonas</i> strains that exhibited different adhesion abilities, leading to the identification of an adhesion regulatory network involving flagellar assembly regulation, bacterial chemotaxis, quorum sensing, two-component systems, biofilm formation, and bacterial secretion systems. This study identified the <i>Pseudomonas</i> adhesion regulatory pathway and determined 10 key adhesion-related genes.