Shelf-life extension of turbot using theaflavin-3,3'-digallate: A growth-neutral quorum sensing inhibitor targeting Hafnia alvei

The spoilage of refrigerated aquatic products by resilient psychrotrophic bacteria like Hafnia alvei poses a major challenge to the food industry, necessitating green preservation strategies that circumvent antimicrobial resistance. This study demonstrates that theaflavin-3,3'-digallate (TF3), a major black tea polyphenol, functions as a potent anti-virulence agent that specifically disarms the quorum sensing (QS) system of H. alvei H4. Crucially, TF3 at sub-inhibitory concentrations concentration-dependently delayed spoilage in turbot fillets, significantly reducing the rise in pH and total volatile basic nitrogen (TVB-N) and suppressing biogenic amine accumulation, while maintaining Bacterial viability. Mechanistically, TF3 precisely targeted the LuxI synthase with high affinity (Kd = 3.15 μM), inhibiting acyl-homoserine lactone signal synthesis. Integrated multi-omics analyses revealed that QS disruption triggered a cascade of cellular dysregulation: it induced severe oxidative stress, which compromised membrane integrity and fluidity, and paralyzed energy and nucleotide metabolism. This multi-faceted attack collectively disabled the spoilage capacity of H. alvei without imposing a selective pressure for growth resistance. Our findings decipher the growth-neutral mechanism by which a natural food-derived compound achieves bio-preservation, establishing TF3 as a promising, resistance-mitigating strategy for safeguarding aquatic food quality and safety.

Aquatic product preservation; Hafnia alvei; Quorum sensing inhibition; TF3.