Detection of CRSPR-Cas system in Streptococcus thermophilus

Abstract:

[Objective] We aimed to detect the CRSPR-Cas system of six Streptococcus thermophilus. [Methods] Bioinformatics method was used to predict CRSPR-Cas system of nine S. thermophilus that published in National Center for Biotechnology Information. Four primers were designed according to the flanking sequences of standard strains and the CRISPR-Cas system of six S. thermophilus have been detected by PCR method. [Results] S. thermophilus S4 had a Cas9 gene, others all had Cas9 gene, Cas10 gene and Cas9^* gene. In addition, 79 and KLDS3.0207 still had Cas3 gene. [Conclusion] Signature genes amplification of CRSPR-Cas system could predict the type of CRSPR-Cas system in unsequenced strains, these findings will help establish the foundation for the study of CRSPR-Cas system in lactic acid bacteria.