Comparative Effects of the Single and Binary Fermentations of Latilactobacillus sakei and Staphylococcus carnosus on the Growth and Metabolomic Profiles of Fermented Beef Sausages

<i>Latilactobacillus sakei</i> (<i>L. sakei</i>) and <i>Staphylococcus carnosus</i> (<i>S. carnosus</i>) are common starters for fermented sausages. However, the mechanism underlying the effects of these two microorganisms on co-cultivation in sausages remains unclear. This study compared the changes in metabolomics following fermentation by <i>L. sakei</i> and <i>S. carnosus</i> individually and in combination. After two days of fermentation, the pH values of the LS (<i>Latilactobacillus</i> Single), SC (<i>Staphylococcus</i> Single), and LSSC (<i>Latilactobacillus</i>-<i>Staphylococcus</i> Combined) groups were 4.59, 5.19, and 4.86. By comparing the common differential metabolites among the three groups, it was found that the content of N2-acetyl-L-ornithine decreased after single fermentation with <i>L. sakei</i>, while the content of N2-acetyl-L-ornithine increased after single fermentation with <i>S. carnosus</i> and combined fermentation with <i>L. sakei</i>. Additionally, KEGG pathway analysis identified eight key metabolic pathways, including purine metabolism, starch and sucrose metabolism. In addition, it was found that <i>L. sakei</i> produced D-Galactose during fermentation, which could be utilized by <i>S. carnosus</i>. The co-fermentation of <i>L. sakei</i> and <i>S. carnosus</i> promoted the production of D-sorbitol. Our results suggest that the metabolic interactions between <i>L. sakei</i> and <i>S. carnosus</i> increase the number of functional metabolites in co-fermented sausages. These findings provide valuable insights and new research directions for the study of LAB and CNS interactions, as well as for the development of fermentation agents.