A comparative study of protoplast preparation and regeneration in Streptomyces rimosus and Streptomyces lividans.

One of the basic techniques for DNA cloning in Streptomyces is the preparation of protoplasts and the efficient regeneration of normal mycelia. In order to develop an oxytetracycline producing S. rimosus strain as a host for molecular cloning, the efficiencies of protoplast preparation and cell wall regeneration were compared with those obtained using S. lividans, the host for the majority of cloning experiments. The results presented suggest that the S. rimosus strain selected is a convenient host for the cloning of recombinant DNA, at least in relation to the preparation and regeneration of protoplasts. Interestingly, the size of the protoplasts was dependent upon the physiological age of the mycelium in S. rimosus; no such dependence was observed in S. lividans.