Application of adaptive DO-stat feeding control to Pichia pastoris X33 cultures expressing a single chain antibody fragment (scFv)

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Abstract

In this study, fed-batch cultures of a Pichia pastoris strain constitutively expressing a single chain antibody fragment (scFv) under the control of the glyceraldehyde-3-phosphate dehydrogenase (GAP) promoter were performed in a pilot 50 L bioreactor. Due to the very high cell density achieved within the first 75 h, typically between 140 and 160 g-DCW/L of dry cell weight (DCW), most of the scFv is produced under hard oxygen transfer limitation. To improve scFv productivity, a direct adaptive dissolved oxygen (DO)-stat feeding controller that maximizes glycerol feeding under the constraint of available oxygen transfer capacity was developed and applied to this process. The developed adaptive controller enabled to maximize glycerol feeding through the regulation of DO concentration between 3 and 5 % of saturation, thereby improving process productivity. Set-point convergence dynamics are characterized by a fast response upon large perturbations to DO, followed by a slower but very robust convergence in the vicinity of the boundary with almost imperceptible overshoot. Such control performance enabled operating closer to the 0 % boundary for longer periods of time when compared to a traditional proportional-integral-derivative algorithm, which tends to destabilize with increasing cell density.
Original languageUnknown
Pages (from-to)1603-1614
JournalBioprocess and Biosystems Engineering
Volume35
Issue number9
DOIs
Publication statusPublished - 1 Jan 2012

Keywords

    Cite this

    @article{6258e970959f4b5490ca67aff38cbb65,
    title = "Application of adaptive DO-stat feeding control to Pichia pastoris X33 cultures expressing a single chain antibody fragment (scFv)",
    abstract = "In this study, fed-batch cultures of a Pichia pastoris strain constitutively expressing a single chain antibody fragment (scFv) under the control of the glyceraldehyde-3-phosphate dehydrogenase (GAP) promoter were performed in a pilot 50 L bioreactor. Due to the very high cell density achieved within the first 75 h, typically between 140 and 160 g-DCW/L of dry cell weight (DCW), most of the scFv is produced under hard oxygen transfer limitation. To improve scFv productivity, a direct adaptive dissolved oxygen (DO)-stat feeding controller that maximizes glycerol feeding under the constraint of available oxygen transfer capacity was developed and applied to this process. The developed adaptive controller enabled to maximize glycerol feeding through the regulation of DO concentration between 3 and 5 {\%} of saturation, thereby improving process productivity. Set-point convergence dynamics are characterized by a fast response upon large perturbations to DO, followed by a slower but very robust convergence in the vicinity of the boundary with almost imperceptible overshoot. Such control performance enabled operating closer to the 0 {\%} boundary for longer periods of time when compared to a traditional proportional-integral-derivative algorithm, which tends to destabilize with increasing cell density.",
    keywords = "Adaptive process control, Pichia pastoris, GAP promoter, Constitutive protein expression",
    author = "Oliveira, {Rui Manuel Freitas}",
    year = "2012",
    month = "1",
    day = "1",
    doi = "10.1007/s00449-012-0751-z",
    language = "Unknown",
    volume = "35",
    pages = "1603--1614",
    journal = "Bioprocess and Biosystems Engineering",
    issn = "1615-7591",
    publisher = "Springer Science Business Media",
    number = "9",

    }

    TY - JOUR

    T1 - Application of adaptive DO-stat feeding control to Pichia pastoris X33 cultures expressing a single chain antibody fragment (scFv)

    AU - Oliveira, Rui Manuel Freitas

    PY - 2012/1/1

    Y1 - 2012/1/1

    N2 - In this study, fed-batch cultures of a Pichia pastoris strain constitutively expressing a single chain antibody fragment (scFv) under the control of the glyceraldehyde-3-phosphate dehydrogenase (GAP) promoter were performed in a pilot 50 L bioreactor. Due to the very high cell density achieved within the first 75 h, typically between 140 and 160 g-DCW/L of dry cell weight (DCW), most of the scFv is produced under hard oxygen transfer limitation. To improve scFv productivity, a direct adaptive dissolved oxygen (DO)-stat feeding controller that maximizes glycerol feeding under the constraint of available oxygen transfer capacity was developed and applied to this process. The developed adaptive controller enabled to maximize glycerol feeding through the regulation of DO concentration between 3 and 5 % of saturation, thereby improving process productivity. Set-point convergence dynamics are characterized by a fast response upon large perturbations to DO, followed by a slower but very robust convergence in the vicinity of the boundary with almost imperceptible overshoot. Such control performance enabled operating closer to the 0 % boundary for longer periods of time when compared to a traditional proportional-integral-derivative algorithm, which tends to destabilize with increasing cell density.

    AB - In this study, fed-batch cultures of a Pichia pastoris strain constitutively expressing a single chain antibody fragment (scFv) under the control of the glyceraldehyde-3-phosphate dehydrogenase (GAP) promoter were performed in a pilot 50 L bioreactor. Due to the very high cell density achieved within the first 75 h, typically between 140 and 160 g-DCW/L of dry cell weight (DCW), most of the scFv is produced under hard oxygen transfer limitation. To improve scFv productivity, a direct adaptive dissolved oxygen (DO)-stat feeding controller that maximizes glycerol feeding under the constraint of available oxygen transfer capacity was developed and applied to this process. The developed adaptive controller enabled to maximize glycerol feeding through the regulation of DO concentration between 3 and 5 % of saturation, thereby improving process productivity. Set-point convergence dynamics are characterized by a fast response upon large perturbations to DO, followed by a slower but very robust convergence in the vicinity of the boundary with almost imperceptible overshoot. Such control performance enabled operating closer to the 0 % boundary for longer periods of time when compared to a traditional proportional-integral-derivative algorithm, which tends to destabilize with increasing cell density.

    KW - Adaptive process control

    KW - Pichia pastoris

    KW - GAP promoter

    KW - Constitutive protein expression

    U2 - 10.1007/s00449-012-0751-z

    DO - 10.1007/s00449-012-0751-z

    M3 - Article

    VL - 35

    SP - 1603

    EP - 1614

    JO - Bioprocess and Biosystems Engineering

    JF - Bioprocess and Biosystems Engineering

    SN - 1615-7591

    IS - 9

    ER -