Transfer of plasmids and chromosomal genes amongst subspecies of Bacillus thuringiensis

Abstract

The plasmids pBC16 and pC194 from Bacilus thuringiensis subsp. israelensis strains A084-16-194 were transferred to 25 subspecies of B. thuringiensis by a conjugation-like process using broth mating technique. The frequencies of transfer varied considerably between different mating pairs, ranging from 1.1×10 -9 to 9.8×10 -5 . Additionally, chromosomal transfer could also be demonstrated in ten B. thuringiensis subspecies with very low frequencies (4.3×10 -9 to 3.7×10 -7 ). The intersubspecies matings within a group of eight subspecies strains gave higher frequencies of transfer than the matings between the subspecies. Furthermore, the results indicated that the capability to transfer plasmids among these various subspecies did not depend on the presence of large plasmid. © 1990 Society for Industrial Microbiology.