Antibacterial activity and mechanism of mustard essential oil against Pseudomonas fluorescens and Shewanella putrefaciens

Pseudomonas fluorescens and Shewanella putrefaciens are common foodborne pathogens found in aquatic products. The antibacterial efficacy and mechanism of action of mustard essential oil (MEO), which is primarily composed of allyl isothiocyanate (AITC), remain incompletely understood. In this study, we investigated the antibacterial activity of MEO against two bacterial species and explored its mode of action by determining bacterial growth, cellular integrity, metabolomic profiles, and molecular interactions. MEO inhibited the growth of both bacteria, and after 8 h of 2MIC MEO treatment, the electrical conductivity of P. fluorescens and S. putrefaciens increased by 9.028-fold and 11.17-fold, respectively. Metabolomic analyses revealed that MEO significantly altered intracellular metabolite abundances, interrupted the tricarboxylic acid cycle and amino acid metabolism, and inhibited key enzymes. Molecular docking confirmed the specific binding affinities between MEO and key enzymes. In conclusion, MEO exhibits significant potential as an antibacterial agent for controlling the contamination of aquatic products. • • Mustard essential oil (MEO) can inhibit P. fluorescens and S. putrefaciens. • • MEO inhibits P. fluorescens more significantly than S. putrefaciens. • • MEO causes membrane dysfunction by altering membrane permeability and conductivity. • • Pathways associated with amino acid and TCA cycle were mainly disrupted. • • MEO component, AITC, inhibits key metabolic enzymes by interacting with them.