Transformation of Streptomyces lincolnensis protoplasts with plasmid vectors

A method for the preparation and regeneration of protoplasts ofStreptomyces lincolnensis is described. Mycelium in the early exponential phase appeared to be most suitable for this purpose and yielded up to 25 % regenerated intact cells. Transformation ofS. lincolnensis protoplasts was achieved using broad-host-range streptomycete plasmid vectors pIJ622, pMP66, pRS410 and pIJ943 constructed from replacons pIJ101, pSLG33 and SCP2. The efficiency of transformation was 3·103 transformants per μg plasmid DNA when (2–5)·107 recipient protoplasts were used. Interspecific transformations showed that there is no efficient restriction system inS. lincolnensis that would limit the transfer of genetic information fromS. lividans orE. coli.