The bleomycin resistance gene of transposon Tn5 is an excellent marker for transformation of corynebacteria.

Corynebacteria are highly sensitive to the glycopeptide antibiotic bleomycin. The bleomycin resistance gene of transposon Tn5 is expressed very efficiently in Brevibacterium lactofermentum. This gene constitutes an excellent marker for selection of transformants of corynebacteria. The bleomycin resistance gene is expressed from the same promoter as the neomycin resistance gene, which is already used as marker in many vectors of corynebacteria. The promoter of the neo-ble cluster is expressed in a variety of Gram-negative and Gram-positive microorganisms and eucaryotic organisms.