Dna Transfer In Lactobacillus: An Overview

An overview of the fundamental basis for the introduction of DNA into Lactobacillus species is given in this chapter. Natural ways for introducing DNA such as transformation, transduction or conjugation are reported in few strains. No evidence for natural competence is available in particular in probiotic Lactobacillus strains, although various components of natural gene transfer systems are present in various genomes. Protoplast fusion and transfection are also described. The most popular method used for introducing foreign DNA is electroporation, mostly based on cell wall weakening prior to electroshock. The composition of the envelope, in particular the presence or not of an S-layer, and the content of endogenous plasmids in the different Lactobacillus species result in different transformation efficiencies. The use of ssRNA as donor and CRISPR-Cas as the recombineering factor open the way for obtaining recombinants with the need of high efficiency DNA transfer systems to succeed in the genetic modifications.