EFFICIENT TRANSFORMATION OF LACTOBACILLUS-SAKE BY ELECTROPORATION

A procedure to transform intact Lactobacillus sake cells by electropor ation was developed through a systematic examination of the effect of changes in various parameters on the transformation efficiency of Lact . sake strain 64F. The most critical factors were found to be the elec trical parameters, the composition of washing and electroporation/stor age solutions, and the presence of MgCl2 in the expression medium. Und er optimal conditions transformation efficiencies up to 10(7) transfor mants (mu g supercoiled DNA)(-1) were obtained. The optimized procedur e was successfully applied to other Lact. sake strains and consistentl y yielded from 10(4) to 10(7) transformants (mu g supercoiled DNA)(-1) .