Antibiofilm potential of natural agent Coenzyme Q0 against gram-negative pathogens on shrimp and processing surfaces

Biofilm-forming pathogens such as Pseudomonas aeruginosa and Escherichia coli present major food safety risks due to their strong adhesion to processing surfaces and resistance to sanitization. This study evaluated the antibiofilm efficacy of Coenzyme Q0 (CoQ0) on stainless steel, aluminum, silicone rubber, polyethylene terephthalate, and shrimp shell surfaces, as well as in single- and mixed-species biofilms. CoQ0 exhibited minimum inhibitory concentration/minimum bactericidal concentration (MIC/MBC) values of 16/20 μg/mL for P. aeruginosa, 60/64 μg/mL for E. coli, and 100/200 μg/mL for mixed biofilms, with complete eradication achieved at 4 MIC. P. aeruginosa was more sensitive at lower concentrations, whereas E. coli showed a dose-dependent response. Mechanistic assays demonstrated adenosine triphosphate (ATP) depletion, increased reactive oxygen species (ROS) generation, reduced respiratory activity in the triphenyl tetrazolium chloride (TTC) assay, and membrane disruption confirmed by extracellular protein leakage. Nuclear magnetic resonance (NMR) spectroscopy revealed degradation of extracellular polymeric substances (EPS), while reverse transcription polymerase chain reaction (RT-PCR) showed downregulation of biofilm and quorum-sensing genes (algU, rhlR, exoS in P. aeruginosa; rpoS, luxS, csgA in E. coli). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in MA-104 cells confirmed good tolerance up to 60 μg/mL. Confocal laser scanning microscopy (CLSM) and field-emission scanning electron microscopy (FE-SEM) further validated biofilm disintegration and cell damage. Overall, CoQ0 exhibits a multifaceted antibiofilm mechanism with species- and surface-specific effects, supporting its potential as a natural antimicrobial for food safety applications.