Plasmid maintenance in Bacillus stearothermophilus is strain-dependent.
We studied the segregational stability of plasmids based on pTB913, a 4.5-kb rolling-circle plasmid derived from the thermophilic Bacillus plasmid pTB19. In Bacillus stearothermophilus the stability of pTB913 derivatives appeared to be strain-dependent. In strain CU21 large amounts of single-stranded pTB913 DNA were found and the plasmid was highly unstable at 57 degrees C. In strain NUB3621, however, very low amounts of single-stranded plasmid DNA were formed and pTB913-based replicons were only slightly unstable at 57 degrees C. The NUB3621/pTB913 host-vector system seems appropriate for molecular cloning. A RepA-based replicon, also derived from pTB19 but replicating by a theta mechanism, was highly unstable in B. stearothermophilus NUB3621.
Oskam
L
L
Department of Genetics, Centre of Biological Sciences, Haren, Netherlands.
Venema
G
G
Bron
S
S
D004261:DNA Replication; D014644:Genetic Variation; D005822:Genetic Vectors / Q000235:genetics; D001411:Geobacillus stearothermophilus / Q000235:genetics*; D010957:Plasmids / Q000235:genetics*; D014170:Transformation, Genetic