Streptococcus thermophilus strain:ST106 Genome sequencing and assembly

Streptococcus thermophilus ST106 is a Gram-positive, thermophilic lactic acid bacterium. S. thermophilus is commonly used as starter cultures for production of fermented dairy products, but some strains have also been investigated for additional bioactivities. ST106 has been shown to possess a bacteriocin-like peptide (blp) gene cluster on its chromosome; however, as reported for other strains of S. thermophilus, it is unable to naturally produce an antimicrobial peptide. Expression of its broad-spectrum bacteriocin can be induced by supplementing growth medium with a synthetic quorum sensing peptide, encoded by blpC within the blp gene cluster. The current study is being performed to identify the molecular mechanisms that regulate bacteriocin expression in S. thermophilus and determine genetic modifications that would allow for natural expression in these strains. Optimizing the expression of antimicrobial peptides is expected to improve the potential for using S. thermophilus strains for food safety applications.