Static characteristics of a continuous flow bioreactor containing antibiotic‐resistant recombinant cells

Chang, YongKeun; Lim, HC

doi:10.1002/bit.260290806

Cited by 11 publications

(1 citation statement)

References 27 publications

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“…Only a few investigations have dealt with problems important for production. The influence of the dilution ratehpecific growth rate on the plasmid copy number (Seo and Bailey, 1985, 19861, the steady state (Chang and Lim, 1987), cultivation and production in a two-stage reactor system (Park et al, 19891, and effect of acetic acid (Lee et al, 1988(Lee et al, , 1989Kracke-Helm et al, 1991) and amino acids (Mizutani et al, 1986) are some of these investigations. The aim of the present investigation was the characterization of the cultivation of Escherichia coli carrying three different multicopy plasmids and producing a fusion protein SpA::EcoRI where EcoRI decomposes the DNA of the host, with on-line and off-line measurements to find relationships between process variables and process performance.…”

Section: Introductionmentioning

confidence: 99%

Production of Fusion Protein SpA:: EcoRI in Batch Culture in a 60‐L Airlift Tower Loop Reactor

Brandes

Maschke³

et al. 1993

Biotechnology Progress

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Escherichia coli JM103 carrying the expression plasmid pMTC48, repressor plasmid pRK248, and protection plasmid pEcoR4 was grown in a 60-L working volume airlift tower loop reactor on M9 minimal medium. Production of fusion protein SpA::EcoRI was induced by a temperature shift from 30 to 38 (optimum), 40, or 42 degrees C. The following parameters were monitored: cell mass concentration (X), total cell counts (TCC), number of colony-forming units (CFU), concentrations of glucose, acetate, ethanol, pyruvate, lactate, succinate, amino acids, and ammonia, and soluble and total protein content, as well as product concentration (enzyme activity of the fusion protein), dissolved oxygen concentration, oxygen utilization rate (OUR), CO2 production rate (CPR), respiration quotient (RQ), and volumetric mass-transfer coefficients (kLa). Product formation by temperature shift was only observed if LB concentrate was added to the culture at the same time the aeration rate was increased to avoid oxygen-transfer limitation. No product accumulation was observed with glucose and ammonia supplementation. During gene expression, X and TCC increased, CFU decreased, acetate increased, and the primary metabolite (ethanol, pyruvate, lactate) concentrations as well as OUR and CPR passed a maximum while RQ changed only slightly. These facts indicate that, during gene expression, the metabolic activity of the cell passes a maximum, and after that it decreases. With increasing aeration rate, the volumetric productivity increased, but the specific productivity with respect to the cell concentration decreased.

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Section: Introductionmentioning

confidence: 99%

Production of Fusion Protein SpA:: EcoRI in Batch Culture in a 60‐L Airlift Tower Loop Reactor

Brandes

Maschke³

et al. 1993

Biotechnology Progress

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Stability of the pBR322 plasmid derivative pBB210 in Escherichia coli TG1 under non‐selective and selective conditions

Löser

1995

Acta Biotechnologica

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The stability behaviour of the pBR322 plasmid derivative pBB210 withp-lactamase gene and human interferon-a1 gene in Escherichiu coli TG1 was studied in chemostat cultures under non-selective (medium without antibiotics), selective (medium with p-lactam antibiotic ampicillin) and modified selective (medium with ampicillin and thep-lactamase inhibitor sulbactam) conditions. Under non-selective conditions, a behaviour typical of unstable systems was found. Under selective conditions, the behaviour predicted by the models was obtainedthe fraction of plasmid-bearing cells in the population approached a constant value which was dependent on the ampicillin concentration in the feeding and on the cell concentration in the chemostat. Under modified selective conditions, the higher the concentration of sulbactam in the medium was, the higher the fraction of plasmid-bearing cells was in steady state conditions.

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Modelling the stability of the pBR322 plasmid derivative pBB210 in Escherichia coli TG1 under non‐selective and selective conditions

Löser

Ray

1996

Acta Biotechnologica

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A mathematical model has been developed to describe the stability behaviour of the pBR322 plasmid derivative pBB210 with the plactamase gene and the human interferon-a1 gene in Ercherichia coli TG1 under non-selective, selective and modified selective conditions in a chemostat The model was formulated on the basis of experimental investigations. It includes the interaction between plactam antibiotics (ampicillin and sulbactam) and cells (with and without plasmids). in particular the correlation between the growth rate of plasmid-free cells and ampicillin concentration in the medium; ampicillin transport into the periplasm of the plasmid-bearing cells, ampicillin degradation in the periplasm by plasmid-encoded plactamase and the inhibition of the latter by sulbactam. The results obtained by the simulation of chemostat cultivations under various conditions and by steady state analyses are closely related to the results of experiments. Under non-selective conditions, the fraction of plasmid-bearing cells was approaching zero. Under selective and modified selective conditions, a coexistence between plasmid-free and plasmid-bearing cells was reached at steady state. Under these conditions, the steady state fraction of plasmid-bearing cells was proportional to the ampicillin concentration in the feed and inversely proportional to the cell concentration in the chemostat. During highdensity cultivation, a large amount of ampicillin is necessary to suppress plasmid-free cells. Even small concentrations of the plactamase inhihitor sulhactam in the feed increased the steady state fraction of plasmid-bearing cells (from 17.2% to 99.6% at sulbactam-Na concentrations of0 to 5 mg/l).

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Static characteristics of a continuous flow bioreactor containing antibiotic‐resistant recombinant cells

Cited by 11 publications

References 27 publications

Production of Fusion Protein SpA:: EcoRI in Batch Culture in a 60‐L Airlift Tower Loop Reactor

Production of Fusion Protein SpA:: EcoRI in Batch Culture in a 60‐L Airlift Tower Loop Reactor

Stability of the pBR322 plasmid derivative pBB210 in Escherichia coli TG1 under non‐selective and selective conditions

Modelling the stability of the pBR322 plasmid derivative pBB210 in Escherichia coli TG1 under non‐selective and selective conditions

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