Development of gene delivery systems for the ɛ-poly-L-lysine producer, Streptomyces albulus

Streptomyces albulus IFO14147 produces ɛ-poly-L-lysine (ɛ-PL), an amino acid homopolymer antibiotic that is used as a food preservative in many countries, including Japan, South Korea, and the United States. To construct an overproducer of the industrially important ɛ-PL and to develop a deeper understanding of its biosynthetic mechanism, we developed systems for DNA delivery into the S. albulus strain based on both polyethylene glycol-mediated protoplast transformation and intergeneric conjugation from Escherichia coli. The successes of these transformations in particular were accomplished by employing the new cryptic-plasmid-based shuttle vectors constructed in this study. The genetic systems developed here should facilitate a molecular genetic approach to S. albulus.