Streptococcus thermophilus strain ST109 Genome sequencing and assembly

Streptococcus thermophilus ST109 is a Gram-positive, thermophilic yogurt culture that has been reported to produce a broad-spectrum bacteriocin encoded within the chromosomal bacteriocin-like peptide (blp) gene cluster. Several strains of S. thermophilus require induction with a synthetic quorum sensing peptide for production of their blp-encoded bacteriocins; however, ST109 naturally expresses its antimicrobial peptide. The purpose of this study was to identify the molecular mechanisms, which regulate bacteriocin production to understand why expression form the blp gene cluster varies between strains. This may identify targets for genetic modification to allow other strains to naturally produce their bacteriocin, thus increasing their potential as bioprotective cultures.