Easy-Curing and pH-Regulated CRISPR-Cas9 Plasmids for Gene Editing and Plasmid Curing in Lactococcus cremoris.

ABSTRACT: In this work, we developed a plasmid-based CRISPR-Cas9 strategy for editing Lactococcus cremoris, which allows easy generation of plasmid-free strains with the desired modification. We constructed versatile shuttle vectors based on the theta-type pAMβ1 promiscuous replicon and p15A ori, expressing both the Cas9 nuclease gene (under pH-regulated promoters derived from P170) and a single-guide RNA for specific targeting (under a strong constitutive promoter). The vectors designed for plasmid targeting were very effective for low- and high-copy-number plasmid curing in L. cremoris, and their targeting efficiency was shown to be tunable by regulating cas9 expression. For chromosome editing, we implemented a host-independent method that enhances double-homologous recombination events using plas

SUBMITTER: Garay-Novillo JN 

PROVIDER: S-EPMC11662139 | biostudies-literature | 2024 Dec

REPOSITORIES: biostudies-literature