THE EFFECT OF GROWTH-CONDITIONS OF CORYNEBACTERIUM-GLUTAMICUM ON THE TRANSFORMATION FREQUENCY OBTAINED BY ELECTROPORATION

A rapid and efficient method of transforming Corynebacterium glutamicum by electroporation is described. A number of factors are important in determining the level of transformation obtained. Cells grown in the presence of glycine and isonicotinic acid hydrazide and harvested in early exponential growth phase were much easier to transform. The recovery medium on which transformants were isolated also had a significant effect on the number of transformants obtained because cells were osmotically or electrochemically sensitive following electroporation. Transformation efficiencies of up to 5 x 105 transformants per μg plasmid DNA with homologously derived DNA and 2 x 103 transformants per μg of DNA derived from Escherichia coli were obtained.