The factors affecting transformation efficiency of coryneform bacteria by electroporation.

High-voltage electroporation was performed to transfer plasmid DNA of pXZ10145 into different kinds of corynebacteria strains. A number of factors that affected transformation efficiency were investigated. Cells grown in the presence of 4% glycine and harvested in the early exponential growth phase (OD600 was about 0.2) were much more easily transformed. Transformation efficiency up to 8 x 10(6) transformants per microgram of plasmid DNA with homologously derived DNA was obtained. If heterologously derived DNA was used, transformation efficiency was 10(2) to 10(3) times lower than the former one.