CRISPR-Cas in the Cheese Industry

Abstract

Bacteria have evolved a wide range of defense systems to combat phage infections. In the cheese industry, lactic acid bacteria (LAB) used for milk fermentation continuously face threats from phages. Therefore, selecting or developing industrial strains with enhanced phage resistance requires a focus on robust defense systems. Among these systems, the clustered regularly interspaced short palindromic repeats (CRISPR) and their CRISPR-associated proteins (Cas) are notably prevalent in LAB. The early characterization of this adaptive immune system was closely tied to the cheese industry, particularly with Streptococcus thermophilus in which CRISPR-Cas systems are ubiquitous and highly active. This review underscores the contributions of S. thermophilus and its virulent phages to our understanding of the function and mechanisms of CRISPR-Cas systems. Additionally, we review the diversity of CRISPR-Cas systems in LAB used in the cheese industry, the counter-defense strategies employed by dairy phages, and the applications of CRISPR-Cas systems within this sector.