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Stability of Plasmid pHV1431 in Free and Immobilized Cell Cultures. Effect of Temperature
Author(s) -
CRAYNEST MURIEL,
BARBOTIN JEANNOËL,
TRUFFAUT NICOLE,
THOMAS DANIEL
Publication year - 1996
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1111/j.1749-6632.1996.tb40571.x
Subject(s) - plasmid , bacillus subtilis , chemistry , bacteria , recombinant dna , bacillales , bacillus (shape) , microbiology and biotechnology , strain (injury) , biology , chromatography , dna , biochemistry , genetics , anatomy , gene
The segregational and structural stability of pHV1431 has been examined in Bacillus subtilis grown at 30 and 37 degrees C in continuous cultures without selection pressure. Immediately after appearance of plasmid-free cells in the reactor, a competition was observed between bacteria that favored plasmid-free cells because of the faster growth. A stronger instability was found at 30 degrees C compared to that at 37 degrees C. At 30 degrees C after 50 hours of culture, 2% of the cells carried the plasmid, whereas at 37 degrees C this percentage was reached after 130 hours. In both cases, no structural instability was observed. To improve the stability, the recombinant Bacillus subtilis (pHV1431) was immobilized in kappa-carrageenan gel beads. In comparison to free cell systems, a higher cell concentration was obtained. Moreover, the plasmid was maintained stable for longer periods; after 150 hours of culture 40% of cells in the reactor still carried the plasmid at both temperatures.