[Transfer of various markers in Lactobacilli during transformation of plasmid DNA and joint cultivation]

A system providing a high frequency genetic transfer of various markers making the reference strain Lactobacillus buchneri 1837 resistant to Lm, Em and Fus, able to ferment some carbohydrates and antagonistic against Pseudomonas diminuta CCM 2657 was developed. The frequency of the marker transfer during the lactobacilli joint cultivation was 1.5 X 10(-5) = 5.5 X 10(-5) to 1.5 X 10(-4) = 5.5 X 10(-4) which was 3-4 orders of magnitude higher than the marker transfer frequency during transformation of L. buchneri NRRLB 1837 with plasmid DNA of different lactobacilli. The recombinants and transformants resulting from the joint cultivation of lactobacilli contained a plasmid about 60 kb in length which provided cells of L. buchneri NRRLB 1837 with resistance to fusidin, antagonistic activity against Pseudomonas diminuta and capacity for utilizing sucrose and sorbite. It was shown possible to integrate the plasmid DNA about 26.5 kb in length contained in the cells of L. casei MT 205 to the chromosomes of erythromycin resistant transformants. The results of the investigation of the biological properties of the recombinants and transformants and their plasmid profiles were confirmed with the Southern DNA-DNA hybridization.