The DNA transformation in the industrial erythromycin-producing Saccharopolyspora erythraea was investigated as standard protoplast transformation methods are ineffective. Intergeneric conjugal transfer of DNA from E. coli demonstrated transformation efficiencies from 0.05 x 10(-8) to 7.2 x 10(-8) exconjugants generated per recipient. Electroporation-mediated methodologies were also established. More than 10(5) transformants were acquired per mug DNA. The proposed protocol provides an alternative route for the introduction of DNA into industrial strains.