RT Journal Article SR Electronic(1) A1 Nasri, Moncef A1 Berry, Fadwa A1 Sayadi, Sami A1 Thomas, Daniel A1 Barbotin, Jean N.YR 1988 T1 Stability Fluctuations of Plasmid-bearing Cells: Immobilization Effects JF Microbiology, VO 134 IS 8 SP 2325 OP 2331 DO https://doi.org/10.1099/00221287-134-8-2325 PB Microbiology Society, SN 1465-2080, AB The maintenance of the plasmid vectors pTG201 and pTG206 (which both carry the Pseudomonas putida xylE gene) and pBH3 in Escherichia coli hosts was studied in free and immobilized continuous cultures. pTG201, containing the strong λPR promoter, was more quickly lost than plasmid pTG206, containing the tetracycline resistance gene promoter. The instability of pTG201 seems to be related to high expression of the cloned xylE gene. Fluctuations in the proportion of pTG201-containing cells were observed in the free system, suggesting the appearance of adaptive descendants (with and without plasmid) from the initial strains. The loss of plasmid vectors from E. coli cells and the fluctuations in the proportion of plasmid-containing cells could be prevented by immobilizing plasmid-containing bacteria in carrageenan gel beads., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-134-8-2325