A plasmid which does not encode the aminoglycoside phosphotransferase in the butirosin-producing strain of Bacillus circulans.

Bacillus circulans NRRL B-3312 produces the aminoglycoside antibiotic butirosin and encodes an aminoglycoside 3'-phosphotransferase. We detected a 48 kilobase plasmid, pIP850, in this strain; this was analyzed by agarose gel electrophoresis following digestion with EcoRI restriction endonuclease and by nucleic acid hybridization. The results obtained indicate that plasmid pIP850 does not carry the structural gene for the aminoglycoside modifying enzyme.