In metabolic engineering, genome editing tools make it much easier to discover and evaluate relevant genes and pathways and construct strains. Clustered regularly interspaced palindromic repeats (CRISPR)-associated (Cas) systems now have become the first choice for genome engineering in many organisms includingindustrially relevant ones. Targeted DNA cleavage by CRISPR-Cas provides variousgenome engineering modes such as indels, replacements, large deletions, knock-in and chromosomal rearrangements, while host-dependent differences in repair pathways need to be considered. The versatility of the CRISPR system has given rise to derivative technologies that complement nuclease-based editing, which causes cytotoxicity especially in microorganisms. Deaminase-mediated base editing installs targeted point mutations with much less toxicity. CRISPRi and CRISPRa can temporarily control gene expression without changing the genomic sequence. Multiplex, combinatorial and large scale editing are made possible by streamlined design and construction of gRNA libraries to further accelerates comprehensive discovery, evaluation and building of metabolic pathways. This review summarizes the technical basis and recent advances in CRISPR-related genome editing tools applied for metabolic engineering purposes, with representative examples of industrially relevant eukaryotic and prokaryotic organisms.

在代谢工程中，基因组编辑工具使发现和评估相关基因和途径以及构建菌株变得更加容易。成簇的规则间隔回文重复序列 (CRISPR) 相关 (Cas) 系统现在已成为许多生物体（包括工业相关生物体）基因组工程的首选。CRISPR-Cas 靶向 DNA 切割提供了多种基因组工程模式，如插入缺失、替换、大缺失、敲入和染色体重排，同时需要考虑修复途径的宿主依赖性差异。CRISPR 系统的多功能性催生了补充基于核酸酶的编辑的衍生技术，这会导致细胞毒性，尤其是在微生物中。脱氨酶介导的碱基编辑安装了毒性低得多的靶向点突变。CRISPRi和CRISPRa可以在不改变基因组序列的情况下暂时控制基因表达。通过简化 gRNA 文库的设计和构建，使多重、组合和大规模编辑成为可能，以进一步加速代谢途径的综合发现、评估和构建。本综述总结了用于代谢工程目的的 CRISPR 相关基因组编辑工具的技术基础和最新进展，并提供了工业相关真核和原核生物的代表性示例。