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Effect of feed cycling on plasmid stabilization during continuous fermentation: The case of variable plasmid loss probability
Author(s) -
Patnaik P. R.
Publication year - 1994
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450720521
Subject(s) - dilution , plasmid , fermentation , chemistry , constant (computer programming) , biological system , thermodynamics , control theory (sociology) , mathematics , biology , physics , biochemistry , dna , computer science , control (management) , artificial intelligence , programming language
The effect of feed cycling on the stability of plasmid‐bearing cells during continuous fermentation has been analysed for the case where the probability of loss of the plasmid varies with time. The model consists of a system of delayed differential equations. By using a square‐wave profile of the dilution rate, a two‐fold increase in the concentration of plasmid‐bearing cells and the recombinant product can be achieved over what is possible with a constant dilution rate. The dilution rate has a stronger effect than the frequency. These results agree qualitatively with reported experiments. The plasmid loss probability and the differential growth rate show fluctuations for a square‐wave variation in the dilution rate, and even with a constant dilution rate they stabilise only after a length of time. These observations show that it is particularly important to account for variable plasmid loss probability in the initial phase of fermentation.