The invention is directed to a lactose-positive, galactose-negative, Streptococcus thermophilus strain releasing glucose during milk fermentation. This Streptococcus thermophilus strain carries mutation in the glcK gene, in the ccpA gene, in the lacZ gene and/or in the ptsH gene, and optionally in one or more genes, in particular one gene, encoding a protein of the mannose-glucose-specific PTS. The invention also concerns a composition comprising at least one, lactose-positive, galactose-negative, Streptococcus thermophilus strain of the invention, and the use of this strain or composition to manufacture a fermented dairy product.
