Protoplasts of Bacillus subtilis 168 trpC2 str and cells of Escherichia coli SK 1590 after treatment with calcium chloride were transformed to tetracycline resistance with the recombinant plasmid pUN82 entrapped in the reverse phase evaporation liposomes. Frequency of transfer was 4 X 10(-4)% in B. subtilis and 8 X 10(-6)% in E. coli.
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