Non-targeted metabonomics reveals the effect of linalyl alcohol on Brochothrix thermophile and its potential application

Brochothrix thermophcta (B. thermophcta) is a pathogenic microorganism associated with food contamination. Linalyl alcohol, owing to its broad spectrum and exceptional antibacterial properties, is regarded as a potent natural antimicrobial agent. This is to elucidate the cellular-level mechanism of linalyl alcohol on B. thermophacta and investigate, for the first time, its regulatory effect on the metabolic pathway of B. thermophacta through metabonomics analysis. The results demonstrated that treatment with linalyl alcohol led to a reduction in bacterial metabolic capacity, while simultaneously promoting an increase in membrane fluidity through damage to the bacterial cell membrane. A total of 201 differential metabolites were identified at the metabolic level, with 50 showing significant up-regulation and 151 displaying significant down-regulation. The differential metabolites primarily participate in the tRNA cycle, amino acid metabolism, nucleotide metabolism, and aminoacyltRNA biosynthesis, with a particular emphasis on the significant impairment of amino acid metabolism. The application results demonstrated that linalyl alcohol exhibited a significant antibacterial effect on B. thermosphacta, as evidenced by the negligible changes observed in the color, smell, and tissue state of pork even after 8 days of treatment. In summary, linalyl alcohol exhibits multi-target and multi-pathway inhibition against B. thermosphacta, leading to disruption of cell morphology and metabolic processes. These findings provide a novel theoretical foundation for understanding the inhibitory mechanism of linalyl alcohol on B. thermosphacta, highlighting its potential as an effective alternative to food additives in the preservation industry of livestock products.