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.

嗜热链球菌ST109是一种革兰氏阳性、嗜热型酸奶培养菌，据报告其基因组内含有编码广谱抗菌肽的染色体级抗菌肽样肽（blp）基因簇。多种嗜热链球菌菌株需要通过合成群体感应肽的诱导来生产其blp编码的抗菌肽；然而，ST109菌株能够自然表达其抗菌肽。本研究的目的是鉴定调节抗菌肽生产的分子机制，以理解为何不同菌株之间blp基因簇的表达形式存在差异。这或许能够识别遗传改良的靶点，使其他菌株能够自然生产其抗菌肽，从而增强其作为生物保护性菌株的潜力。