The Barrangou laboratory focuses on the biology and genetics of CRISPR-Cas immune systems in bacteria. Using microbiology, molecular biology and genomics approaches, we investigate the use of CRISPR-Cas systems for three types of applications: 1) The exploitation of CRISPR spacer hypervariability for genotyping and phylogenetic studies of beneficial and pathogenic bacteria; 2) Leveraging CRISPR-mediated interference for building up phage resistance in probiotic strains and starter cultures used in food manufacturing; and 3) Harnessing of Cas9-mediated, re-programmable dsDNA cleavage for genome editing in bacteria. These activities provide insights into the genetic and molecular processes that drive CRISPR-mediated adaptive immunity in bacteria and generate novel tools for the manipulation of industrially relevant organisms for food and biotechnological applications.