High efficiency electroporation of intact Corynebacterium glutamicum cells

Abstract High‐frequency electroporation of whole Corynebacterium glutamicum cells without enzymatic pretreatment was achieved. Under optimized conditions concerning growth stage, washing of cells, cell concentration and pulse parameters transformation efficiencies of far more than 10⁷ transformants per μg pWST4B plasmid DNA were reached. Using electroporation, linearised and subsequently religated plasmid as well as chimeric ligase reaction products were directly introduced into C. glutamicum with reasonable efficiencies. Electrotransformation efficiency was reduced about 10⁵‐fold for plasmid DNA cycled through E. coli JM83. Restriction deficient mutants of C. glutamicum were isolated which could be efficiently transformed with foreign DNA.