Improved procedure for the transformation of the entomopathic microorganism Bacillus sphaericus

Abstract Previous studies of the mosquito larvicidal bacterium Bacillus sphaericus 1593 have shown that this organism can be transformed with plasmid DNA, although at extremely low freqencies. In this paper, we report the use of a sucrose-based regeneration medium following plasmid transformation of B. sphaericus 1593 protoplasts. This modification greatly improved both the transformation frequency and the regeneration rate of the transformants.