Comparative genomic analysis between Lactobacillus delbreuckii subsp. lactis and Lactobacillus delbreuckii subsp. bulgaricus of dairy origin

Lactobacillus delbreuckii subsp. lactis and Lactobacillus delbreuckii subsp. bulgaricus are lactic acid bacteria commonly exploited by the dairy industry as starter cultures, mainly for the production of cheese and yogurt. In this work, we present the comparative genomic analysis between the recently sequenced genomes of L. lactis ACA-DC 178 and L. bulgaricus ACA DC 87, isolated from Kasseri cheese and yogurt, respectively. The genome of L. lactis ACA-DC 178 is larger than that of L. bulgaricus ACA-DC 87, containing 2,048 and 1,928 protein coding genes, respectively. Full chromosome alignments revealed strain specific differences, although a high degree of synteny between the two strains was also observed. The core genome of the two stains contained about 1,300 genes while the unique genes of the two strains were als oidentified. The two genomes contained several genomic islands, indicating that a number of genes have been acquired through horizontal gene transfer. We also predicted one confirmed CRISPR system in each genome, three potential antimicrobial peptides in total and also prophage sequences integrated into the genomes of the two strains. Overall,our analysis provides useful insights into the technological potential of the ACA-DC 178 and ACA-DC 87 strains