A. Dunn et al., AN ANALYSIS OF THE INSTABILITY KINETICS OF PLASMID PHSG415 DURING CONTINUOUS-CULTURE OF ESCHERICHIA-COLI, Microbiology, 141, 1995, pp. 63-70
The effect of dilution rate on the instability kinetics of Escherichia
coli RV308(pHSG415) during glucose-limited continuous culture is exam
ined. Two nonlinear models are fitted to the data, both of which chara
cterize the plasmid-host system in terms of the rate parameters R (for
the plasmid segregation rate) and d mu (for the specific growth rate
difference between plasmid-free and plasmid-bearing single cells). In
the first model, both R and d mu have constant values with respect to
time. In the second, either R or d mu is represented as a time-depende
nt function. Although both models fit the data equally well, it is dem
onstrated that the constant rate parameter model gives results which a
ppear to be misleading. a comparison is also made among some of the ma
ny plasmid instability models (both mass-balance and segregated) which
)rave appeared in the literature, It is found that all of these give i
dentical trajectories and differ only in the definitions of the rate p
arameters used.