Plasmid deoxyribonucleic acid in strains of Bacillus sphaericus and in Bacillus moritai

Bacillus moritai and six strains of Bacillus sphaericus pathogenic to dipteran larvae were examined for the presence of covalently closed circular (CCC) DNA. The plasmid profiles of the bacteria were analyzed using a cleared lysate electrophoresis technique. Four of the six strains of B. sphaericus examined contained CCC DNA. Strain SSII-1 contained two plasmids (pKA1, pKA2) having molecular weights of about 8.4 and 2.0 megadaltons (MDa). Strains 1404 and 1881 each contained one plasmid, pKA3 and pKA4, respectively. pKA3 had a molecular weight of about 8.2 MDa. pKA4 had a relatively large plasmid with a molecular weight of about 33.5 MDa. Strain K contained five size classes of CCC DNA. The plasmids pKA5, pKA6, pKA7, pKA8, and pKA9 had molecular weights of about 11.4, 10.9, 7.4, 7.0, and 6.4 MDa, respectively. Strains 1593-4 and 1691 were plasmidless and could not be distinguished from each other based on their plasmid profiles. B. moritai ATCC 21042 contained two size classes of CCC duplex DNA; pRF100 had a molecular weight of about 4.6 MDa and pRF101 had a molecular weight of about 2.1 MDa. No phenotype association with any of the isolated plasmids has been determined.