Location: Dairy and Functional Foods ResearchTitle: Complete genome sequences of bacteriocin-producing streptococcus thermophilus strains ST016 and ST109
Submitted to: Microbiology Resource Announcements
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/4/2019
Publication Date: 2/14/2019
Citation: Renye Jr, J.A., Needleman, D.S., Steinberg, D.H. 2019. Complete genome sequences of bacteriocin-producing streptococcus thermophilus strains ST016 and ST109. Microbiology Resource Announcements. 8:1-2. https://doi.org/10.1128/MRA.01336-18.
Interpretive Summary: Streptococcus thermophilus is a dairy culture commonly used for production of yogurt and cheese. Some of these cultures have been shown to produce compounds which prevent the growth of harmful bacteria associated with human illness. This study reports the complete DNA sequences for two yogurt cultures capable of producing an antibacterial compound. A comparison of the DNA sequences revealed they were highly similar; however, only one culture, designated ST109, naturally produced its antibacterial compound. Further analysis of the DNA sequences predicted that the other culture, ST106, possessed more genes which were nonfunctional; however further studies are required to determine if these nonfunctional genes would be expected to regulate the production of antibacterial compounds.
Technical Abstract: Streptococcus thermophilus strains ST106 and ST109 have been shown to produce bacteriocins encoded within the bacteriocin-like peptide (blp) gene cluster. Strain ST109 naturally produces its broad-spectrum bacteriocin; however, strain ST106 requires induction with a synthetic signaling peptide to produce its antimicrobial peptide. The blp gene clusters within these strains differ by only 36 nucleotides, including an 18 bp deletion upstream of orf3 in strain ST109, suggesting that bacteriocin expression may be regulated by factors encoded elsewhere on the chromosome. The complete genome sequence for strain ST109 contains 1,788,866 nucleotides, 1,572 predicted genes, and an average G+C content of 39.2%, while the ST106 chromosome contains 1,856,083 nucleotides, 1,601 predicted genes, and an average G+C content of 39.3%.