Quorum sensing inhibition by citronellol reduces Aeromonas salmonicida biofilm formation and prolongs the shelf life of Scophthalmus maximus fillets during cold storage

Microbe-mediated food spoilage caused by Aeromonas salmonicida poses a major challenge in the food industry, as it produces virulence factors (e.g., proteases, hemolysins, and biofilms) that accelerate deterioration. In this study, citronellol, a natural monoterpene alcohol, was evaluated as a potential quorum sensing inhibitor (QSI) to mitigate spoilage in Scophthalmus maximus (turbot) fillets. Citronellol effectively suppressed A. salmonicida virulence factors, biofilm formation, and motility, reducing protease activity by 45.65%, hemolysin production by 84.77%, and swarming motility by 53.51% at 160 μg/mL. Additionally, it inhibited C4-HSL synthesis by 87.49%. In refrigerated S. maximus fillets, citronellol significantly lowered spoilage indicators, including TVB-N by 24.10%, TBA by 34.89%, and TMA by 53.51%. Molecular docking indicated that citronellol, particularly its (R)-enantiomer, stably binds key residues in QS-related proteins (e.g., LuxS) via hydrogen bonds and hydrophobic interactions. These findings suggest that citronellol disrupts the QS system in A. salmonicida , showing potential as a natural, sustainable preservative to extend the shelf life of S. maximus fillets and reduce seafood waste. • Citronellol inhibits A. salmonicida biofilm and quorum sensing at sub-MIC levels. • Citronellol reduces spoilage markers in turbot fillets during cold storage. • Molecular docking reveals LuxS as a potential QS target of citronellol.