EXTRACHROMOSOMAL DNA IN BACILLUS-THURINGIENSIS VAR KURSTAKI, VAR FINITIMUS, VAR SOTTO, AND IN BACILLUS-POPILLIAE

Four entomopathogenic bacteria contained extrachromosomal deoxyribonucleic acid (DNA) molecules of various sizes. Bacillus thuringiensis var. kurstaki contained twelve elements banding on agarose gels that ranged from 0.74 to > 50 × 106 daltons, three of which were giant extrachromosomal DNA elements. B. thuringiensis var. sotto contained one giant extrachromosomal DNA element with a molecular size of about 23.5 × 106 daltons and two lesser elements of 0.80 and 0.62 × 106 daltons. B. thuringiensis var. finitimus harbored two giant DNA elements corresponding to >50 × 106 daltons and two lesser bands with relative small size (0.98 and 0.97 × 106 daltons). B. popilliae contained no giant extrachromosomal DNA elements but did contain two smaller elements corresponding to 4.45 and 0.58 × 106 daltons. The possible use of extrachromosomal DNA elements that prove to be autonomous replicons for recombinant DNA studies is discussed. © 1979.