Unraveling the antibacterial mechanism of exogenous autoinducers against Shewanella putrefaciens revealed by metabolomics and its potential application on preserving large yellow croaker (Pseudosciaena crocea).

Abstract

Specific spoilage organisms (SSOs) play a crucial role in causing the deterioration of aquatic products. This study investigated the antibacterial activity and mechanism of exogenous autoinducers through biochemical and metabolomics analysis against Shewanella putrefaciens. The potential application of exogenous autoinducers on large yellow croaker preservation was further investigated. C4-HSL, C10-HSL and C14-HSL with the strongest antibacterial activity on S. putrefaciens were selected, from the aspects of growth curve, biofilm formation, and motility ability, which damaged the integrity of cell membrane. Metabolomics analysis demonstrated C10-HSL significantly affected key metabolic pathways including alanine, aspartate and glutamate metabolism, glycine, serine and threonine metabolism, arginine biosynthesis, phenylalanine metabolism, tricarboxylic acid (TCA) cycle, pyrimidine and purine metabolism. Furthermore, C10-HSL exhibited the most effective preservation performance for large yellow croaker. These findings highlighted the antibacterial mechanism of exogenous acylated homoserine lactones (AHLs) and confirmed the potential of exogenous AHLs to prolong the shelf-life of aquatic products.