植物乳植杆菌CRISPR基因座分析OA

The CRISPR/Cas system is an acquired immune system of bacteria and has been an important gene editing tech-nology in the field of synthetic biology.However,at present,the analysis and application of CRISPR/Cas system of lactic acid bacteria remain insufficient.This study analyzed the CRISPR/Cas9 system of Lactiplantibacillus plantarum TCCC11824,a novel probiotic strain isolated in our previous study,and 12 other strains of the same genus.The results showed that the CRISPR system types of the 13 strains of L.plantarum were all Type ⅡA,with characteristic Cas9,Cas1,Cas2 and Csn2 genes flanking the CRISPR sequence.The tracrRNA was predicted to be located between Cas9 and Cas1,while the repeats differed from each other and could form a stable secondary structure of 5 or 7 bases.Among them,the spacer sequences in the CRISPR sequences of 8 strains of L.plantarum could collectively target a total of 12 phages.The most efficient PAM sequence for L.plantarum Cas9 protein recognition was CC.This study helps to understand the mech-anism of lactic acid bacteria to resist genetic infection during the evolutionary process,and lays a foundation for the devel-opment of efficient gene editing systems.