[Isolation and characteristics of plasmid DNA from Lactobacilli].

It was shown on a model of 2 collection strains of lactobacilli that their cultivation on a synthetic multicomponent medium with addition of threonine and subsequent exposure of the cells to lysozyme at 0 degrees C and to alkaline solution of sodium dodecylsulfate at 60 degrees C provided highly efficient detection of plasmid DNA in these organisms. Circular molecules of the plasmid DNA of the 7-kv length, their dimer forms and linear molecules were detected in both of the strains.