Influence of glycine betaine on the transfer of plasmid RP4 between Escherichia coli strains in marine sediments.

The conjugative transfer of plasmid RP4 between two strains of Escherichia coli in a sterile marine sediment was enhanced by the presence of glycine betaine (frequency increased 20 to 40 times). The conjugation was also facilitated by the osmoprotection of donor cells. Glycine betaine is a universal osmolyte and has been found in marine sediments at high concentrations. So this phenomenon could have epidemiological and sanitary importance by increasing the possibility of dissemination of some plasmids present in enterobacteria in natural marine deposits.