In Silico Comparative Genomic Analysis Revealed a Highly Conserved Proteolytic System in .

, the type species of the genus , is widely recognized as the primary starter culture in the dairy industry due to its proteolytic activity, which enables it to growth in milk. In this study, a comprehensive genomic analysis of the proteolytic system was conducted on strains. The analysis included 27 genomes of , with a specific focus on the key enzyme involved in this system, the cell envelope-associated proteinase (CEP). The amino acid sequences, as well as the protein-structure prediction of the CEPs, were compared. Additionally, syntenic analysis of the genomic locus related to the CEPs revealed high conservation in subsp. strains, while subsp. strains exhibited greater variability, including the presence of insertion sequences, deletions, and rearrangements. Finally, the CEP promoter region and putative regulatory elements responsible for controlling the expression of the proteolytic system in lactobacilli were investigated. Our genomic analysis and characterization of the CEPs contribute to our understanding of proteolytic activity and the potential applications of these lactic acid bacteria in the dairy industry. Further research in this area will expand our knowledge and potential practical uses of these findings.