The use of CRISPR-Cas-based systems in bacterial cell factories

Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)-Cas system has been the focus since its first introduction to genome editing research. It acts as an adaptive immune system in many prokaryotes by detecting and degrading viral/invasive DNA/RNA repurposed for targeted genome editing in various organisms, including bacterial species relevant to industrial biotechnology. Targeted genome editing in bacteria has been implemented for multiple purposes, such as method development, understanding knowledge of metabolic processes and improving the productivity of industrial products. With the increasing share of biotechnological products, bacteria have been the subject in the field of genome editing. This review summarizes the immunological mechanisms of CRISPR-Cas systems, the variation in classification of CRISPR-Cas systems by highlighting their features and the current applications of CRISPR-based genome editing in industrially relevant bacteria. In addition, an extensive literature review focused on recent advances has been presented in bacterial species according to industrial significance.