Analysis of CRISPR-Cas Loci and their Targets in Levilactobacillus brevis

AbstractThe CRISPR ‒Cas system acts as a bacterial defense mechanism by conferring adaptive immunity and limiting genetic reshuffling. However, under adverse environmental hazards, bacteria can employ their CRISPR‒Cas system to exchange genes that are vital for adaptation and survival.Levilactobacillus brevis is a lactic acid bacterium with great potential for commercial purposes because it can be genetically manipulated to enhance its functionality and nutritional value. Nevertheless, the CRISPR ‒Cas system might interfere with the genetic modification process. Additionally, little is known about the CRISPR‒Cas system in this industrially important microorganism. Here, we investigate the prevalence, diversity, and targets of CRISPR‒Cas systems in the genusLevilactobacillus, further focusing on complete genomes ofL. brevis. Using the CRISPRCasFinder webserver, we identified 801 putative CRISPR-Cas systems in the genusLevilactobacillus. Further investigation focusing on the complete genomes ofL. brevis revealed 54 putative CRISPR-Cas systems. Of these, 46 were orphan CRISPRs, and eight were CRISPR ‒Cas systems. The type II-A CRISPR‒Cas system is the most common inLevilactobacillus andL. brevis complete genomes. Analysis of the spacer ’s target showed that the CRISPR‒Cas systems ofL. brevis mainly target the enterococcal plasmids.Graphical AbstractComparative analysis of putative CRISPR-Cas loci inLevilactobacillus brevis
Source: Interdisciplinary Sciences, Computational Life Sciences - Category: Bioinformatics Source Type: research