Metabolomics and gene-metabolite networks reveal the potential of Leuconostoc and Weissella strains as starter cultures in the manufacturing of bread without baker’s yeast

Lactic Acid Bacteria (LAB) could provide a valid alternative to S. cerevisiae as a starter culture for bakery products, avoiding yeast-related health problems while contributing to the technological and functional properties of bread. In this work, we evaluate the role of certain LABs (Leuconostoc citreum SB6, Weissella cibaria UC4051, Weissella confusa UC4051, and the commercial starter cultures Weissella cibaria, and Leuconostoc mesenteroides) in producing functional compounds (pro-technological, health-promoting, and postbiotic-like molecules). For this purpose, we analysed the genotypic and phenotypic features of strains, and we investigated dough fermentation from microbiological and metabolomics approaches. Results evidenced a clear discrimination between the metabolic activity of baker’s yeast and LAB. The most discriminant metabolites derived from proteolysis and lipolysis, such as peptides, amino acids, and fatty acyls. Furthermore, we elucidated the different metabolism of these strains by building gene-metabolite interaction networks that pairwise compared the LAB strains of the same genus. While most of the networks showed a characteristic nucleotide metabolism, only the commercial W. cibaria exhibited an interaction network composed of amino acids and their related genes. In conclusion, our findings reveal that LAB strains under investigation, and particularly the commercial W. cibaria, can enhance the functional properties of bread.