Control of specific carbon dioxide production in a fed-batch culture producing recombinant protein using a soft sensor.
The feeding of a fed-batch cultivation producing recombinant protein was controlled by a soft sensor set-up. It was assumed that the control approach could be based on the cell's production of carbon dioxide and that this parameter indicates the metabolic state occurring at induced protein expression. The soft sensor used the on-line signals from a carbon dioxide analyser and a near-infrared (NIR) probe for biomass to estimate the specific production rate qCO2. Control experiments were carried out with various qCO2 set-points where we observe that the feeding of nutrients to the culture could easily be controlled and resulted in a decreased variability compared to uncontrolled cultivations. We therefore suggest that this control approach could serve as an alternative to other commonly applied methods such as controlling the cell's overflow metabolism of acetate or the cell's specific growth rate. However, further studies of the internal metabolic fluxes of CO2 during protein expression would be recommended for a more precise characterization of the relationship between qCO2 and protein expression in order to fully interpret the control behaviour.
Division of Biotechnology, IFM, Linköping University, 581 83 Linköping, Sweden.
Robert
R
Gustavsson
Division of Biotechnology, IFM, Linköping University, 581 83 Linköping, Sweden.
Cornelia
C
Lukasser
Division of Biotechnology, IFM, Linköping University, 581 83 Linköping, Sweden. Electronic address: cfm@ifm.liu.se.
Carl-Fredrik
CF
Mandenius
D061249:Batch Cell Culture Techniques; D018533:Biomass; D019149:Bioreactors; D002245:Carbon Dioxide / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism*; D009862:Online Systems; D011994:Recombinant Proteins / Q000378:metabolism
D011994:Recombinant Proteins; D002245:Carbon Dioxide; D049452:Green Fluorescent Proteins
Bioprocess regulation; Carbon dioxide production rate; Monitoring; Reproducibility; Software sensor; Variance