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

Abstract

This study aimed to investigate the molecular mechanism of Pseudomonas with varying adhesion capabilities to Tilapia's intestinal mucus influence the spoilage potential of Tilapia. Sodium chloride(NaCl) was used as an environmental factor to regulate Pseudomonas' 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 flgC, fliC, and cheB, was found to be altered. LP-3, with high adhesion ability, was observed to promote a relative increase in Nocardioides and Cloacibacterium 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 Pseudomonas 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 Pseudomonas adhesion regulatory pathway and determined 10 key adhesion-related genes.