The effect of the partition locus on plasmid stability and expression of a prolonged chemostat culture.
The stability, copy number, and gene expression of the pBR322 plasmid containing the par-locus under prolonged cultivation were studied. In the initial stage of the experiment it was observed that the par-locus had a stabilization effect on plasmid maintenance. This observation was consistent with previously reported results. However, after approximately 225 h, a mixed population of plasmid-containing and plasmid-free cells appeared. The mixed culture was stably maintained for approximately 200 h. In addition, the relative plasmid copy number showed an increase as compared to the par- culture. After 100 h the copy number decreased, reached a minimum, then stabilized. The beta-lactamase activity, was not significantly affected by the par-locus.
Department of Chemical Engineering, Rice University, Houston, Texas 77251-1892.
A E
AE
Weber
P
P
Yu
K Y
KY
San
D001483:Base Sequence; D003470:Culture Media; D008969:Molecular Sequence Data; D010957:Plasmids; D001618:beta-Lactamases / Q000378:metabolism
D003470:Culture Media; D001618:beta-Lactamases