HIGH-EFFICIENCY INTRODUCTION OF PLASMID DNA INTO GLYCINE TREATED ENTEROCOCCUS-FAECALIS BY ELECTROPORATION

A highly efficient electroporation system for Enterococcus faecalis was developed by systematically optimizing different parameters. One parameter found to be particularly critical for electroporation was cultivation of E. faecalis in medium containing a high glycine concentration, prior to electroporation. Osmotic stabilization of cells with 0.5 M sucrose was also found to be critical during glycine treatment. 106 transformants per microgram of plasmid DNA were consistently obtained within 48 h. Electrocompetent preparations of E. faecalis could be stored at -70° C without loss of competence. © 1990 Springer-Verlag.