CRISPR-based gene editing technology and its application in microbial engineering

Gene editing technology involves the modification of a specific target gene to obtain a new function or phenotype.Recent advances in clustered regularly interspaced short palindromic repeats(CRISPR)-Cas-mediated technolo-gies have provided an efficient tool for genetic engineering of cells and organisms.Here,we review the three emerging gene editing tools(ZFNs,TALENs,and CRISPR-Cas)and briefly introduce the principle,classification,and mechanisms of the CRISPR-Cas systems.Strategies for gene editing based on endogenous and exogenous CRISPR-Cas systems,as well as the novel base editor(BE),prime editor(PE),and CRISPR-associated transposase(CAST)technologies,are described in detail.In addition,we summarize recent developments in the application of CRISPR-based gene editing tools for industrial microorganism and probiotics modifications.Finally,the potential challenges and future perspectives of CRISPR-based gene editing tools are discussed.