Table 1.

CRISPR-assisted recombineering systems.

CRISPR tools	Host cells	Vectors	Repair mechanisms	Ref.
Single-strand DNA recombineering (SSDR)	E. coli; Lactobacillus reuteri	pCas9 plasmid carrying tracrRNA, Cas9 and a resistance cassette, and a pCRISPR kanamycin-resistant plasmid carrying CRISPR spacers.	Homologous recombination	[15], [17]
Double-strand DNA recombineering (DSDR)	E. coli;	λ-Red and SpyCas9 expressing vector and gRNA expressing plasmid	Homologous recombination	[18]
Non-recombineering-based Homologous Recombination (NrHR)	Clostridium cellulolyticum	Vector pCas9 expressing Cas9 nickase (D10A), and vector pGRNA expression guide RNA	Nickase, single-nick-triggered homologous recombination	[54], [55]
Non-Homologous End Joining (NHEJ)	Actinomycetales	pCRISPRCas9 for gene deletion or replacement, and pCRISPR-dCas9 for gene expression control; and vector pCRISPR-sgRNA carrying sgRNA scaffold	Non-homologous end joining	[56]