Unveiling the Genetic Basis and Metabolic Rewiring Behind the Galactose-Positive Phenotype in a Streptococcus thermophilus Mutant

Streptococcus thermophilus (S. thermophilus) is a widely used starter culture in dairy fermentation, but most strains are galactose-negative and only metabolize glucose from lactose hydrolysis. In this study, we aimed to uncover the mechanisms underlying the acquisition of a stable galactose-positive (Gal