High-efficiency transformation of Bacillus subtilis NB22, an antifungal antibiotic iturin producer, by electroporation

High-voltage electroporation was used to transform Bacillus subtilis NB22, an antifungal antibiotic producer, reaching the efficiency of 107 transformants/μg plasmid DNA. Transformation frequency was dependent on the composition of the electroporation solution, the electrical field strength and the cell concentration. Addition of polyethylene glycol (PEG) and mannitol in the transformation solution was critical for a high efficiency of transformation.