Essential oil components inhibit biofilm formation in Erwinia carotovora and Pseudomonas fluorescens via anti-quorum sensing activity

The effect of 10 essential oil (EO) components on biofilm formation for vegetable spoilage Erwinia carotovora and Pseudomonas fluorescens at sub-MICs were investigated. Chromobacterium vlolaceum CV026 (CV026) was selected as quorum sensing (QS) biosensor bacterium. The swimming, swarming, twitching motility, exopolysaccharide (EPS) production and biofilm formation were determined. All tested EO components showed QS inhibition of CV026, K carotovora and P. fluorescens. Biofilms were inhibited by all EO components by inhibiting their motilitles and BPS production. Salicylic acid and thymol showed the best inhibitory effect on biofilm formation of P. fluorescens (37.61%) and E. carotovora (47.24%) respectively. Hexanal as QS inhibitor for biofilm formation was first reported, with inhibition ratio of 25.86% and 20.18%, which was confirmed by scanning electron and fluorescence microscopy. Inhibition of biofilm formation by anti-QS SO components could be novel intervention strategy to enhance safety and quality of vegetables in the food industry.