Pilot-scale verification of a computer-based simulation for the centrifugal recovery of biological particles

Clarkson, A. I.; Bulmer, M.; Titchener-Hooker, NJ

doi:10.1007/bf00387961

Cited by 30 publications

(22 citation statements)

References 15 publications

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“…Extensive analysis showed that this was most likely to be due to the inability of the simulations to account for the extent of precipitate breakage occurring as the suspension entered the disk-stack centrifuge at the point of recovery of the first precipitate cut. Such shear-breakage caused a reduction in the particle diameter which in turn leads to poorer recovery than predicted in the model; since the centrifuge is actually separating a particle size distribution smaller than the inlet particle size distribution (Bell and Brunner, [3]; Clarkson et al, [9]) on which the separation efficiency is based. As the level of recovery falls so carry-over of contaminating solids (low solubility protein) into the second fractionation step occurs, figure 1.…”

Section: Resultsmentioning

confidence: 99%

“…All simulations were carried out as described previously by Clarkson et al, [8,9] using a series of steady state models encoded in SPEEDUP (AspenTech, Cambridge, UK). Results consisted of total masses and concentrations for each component in all of the process streams.…”

Section: Simulationsmentioning

confidence: 99%

“…Disk-stack centrifugation modelling was derived from the grade efficiency concept and includes correction terms to account for hindered settling at high solids concentrations (Clarkson et al, [9]; Mannweiler, [18]). The models used to describe batch precipitation employ a semi-empirical equation (Niktari et al, [19]) for predicting the protein and enzyme solubility behaviour and a discretised population balance model for predicting the precipitate particle size distributions during ageing (Clarkson et al, [8]).…”

Section: Introductionmentioning

confidence: 99%

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Computer-based simulation of the recovery of intracellular enzymes and its pilot-scale verification

Bulmer

Clarkson

Titchener-Hooker

et al. 1996

Bioprocess Engineering

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Accurate and reliable models are required for a range of unit operations if simulations are to be used for accelerating the design and optimisation of bioprocesses. This paper presents results of pilot-plant studies that have been used to verify process simulations for a sequence of operations comprising of cell disruption, fractional protein precipitation and centrifugal separation. These have been tested using the purification of the enzyme alcohol dehydrogenase (ADH) from Saccharomyces cerevisiae as being representative of the recovery of a labile intracellular enzyme. Comparison of pilot-plant against simulated data highlights where improvements to the models are required and has resulted in increased confidence in the simulations for a wide range of conditions including the operational scale and the nature of the starting material. Results demonstrate the effectiveness of the verification approach for the development of reliable predictive models to assess the feasibility of process designs and performance of a train of bioprocess operations. List of symbols

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Section: Resultsmentioning

confidence: 99%

Section: Simulationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Computer-based simulation of the recovery of intracellular enzymes and its pilot-scale verification

Bulmer

Clarkson

Titchener-Hooker

et al. 1996

Bioprocess Engineering

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“…This mimics any break up of material which may occur and which will result in a lowering of the predicted clarification efficiency. Following this, the material is separated in a standard laboratory centrifuge using conditions derived from sedimentation theory (Clarkson et al, 1996;Leung, 1998). The settling velocity, V sg , is related to key materials' and machine properties through Stokes' Law:…”

Section: Ultra Scale-down Centrifugation Approachmentioning

confidence: 99%

A methodology for centrifuge selection for the separation of high solids density cell broths by visualisation of performance using windows of operation

Salte

King

Baganz

et al. 2006

Biotechnol. Bioeng.

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Expression systems capable of growing to high cell densities are now readily available and are popular due to the benefits of increased product concentration. However, such high solids density cultures pose a major challenge for bioprocess engineers as choosing the right separation equipment and operating it at optimal conditions is crucial for efficient recovery. This study proposes a methodology for the rapid determination of suitable operating conditions for the centrifugal recovery of high cell density fermentation broths. An ultra scale-down (USD) approach for the prediction of clarification and dewatering levels achieved in a range of typical high-speed centrifuges is presented. Together with a visualisation tool, a Window of Operation, this provides for the rapid analysis of separation performance and evaluation of the available operating conditions, as an aid in the selection of the centrifuge equipment most appropriate for a given process duty. A case study examining centrifuge selection for the processing of a high cell density Pichia pastoris culture demonstrates the method. The study examines semi-continuous disc-stack centrifuges and batch-operated machines such as multi-chamber bowls and Carr Powerfuges. Performance is assessed based on the variables of clarification, dewatering and product yield. Inclusion of limits imposed by the centrifuge type and design, and operation itself, serve to constrain the process and to define the Windows of Operation. The insight gained from the case study provides a useful indication of the utility of the methodology presented and illustrates the challenges of centrifuge selection for the demanding case of high solids concentration feed streams.

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“…Continuous centrifugation has been widely used for harvest of large-scale cell culture (Berthold and Kempken, 1994;Winter, 2004) and microbial fermentation (Clarkson et al, 1996;Varga et al, 2001) processes in the biopharmaceutical industry. For extracelluar protein product, secondary clarification using depth filter after centrifugation is normally required prior to further downstream processing.…”

Section: Introductionmentioning

confidence: 99%

Comparison of different options for harvest of a therapeutic protein product from high cell density yeast fermentation broth

Wang

Lewus

Rathore

2006

Biotech & Bioengineering

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Recovery of therapeutic protein from high cell density yeast fermentations at commercial scale is a challenging task. In this study, we investigate and compare three different harvest approaches, namely centrifugation followed by depth filtration, centrifugation followed by filter-aid enhanced depth filtration, and microfiltration. This is achieved by presenting a case study involving recovery of a therapeutic protein from Pichia pastoris fermentation broth. The focus of this study is on performance of the depth filtration and the microfiltration steps. The experimental data has been fitted to the conventional models for cake filtration to evaluate specific cake resistance and cake compressibility. In the case of microfiltration, the experimental data agrees well with flux predicted by shear induced diffusion model. It is shown that, under optimal conditions, all three options can deliver the desired product recovery ( >80%), harvest time ( <15 h including sequential concentration/diafiltration step), and clarification ( <6 NTU). However, the three options differ in terms of process development time required, capital cost, consumable cost, ease of scale-ability and process robustness. It is recommended that these be kept under consideration when making a final decision on a harvesting approach.

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Pilot-scale verification of a computer-based simulation for the centrifugal recovery of biological particles

Cited by 30 publications

References 15 publications

Computer-based simulation of the recovery of intracellular enzymes and its pilot-scale verification

Computer-based simulation of the recovery of intracellular enzymes and its pilot-scale verification

A methodology for centrifuge selection for the separation of high solids density cell broths by visualisation of performance using windows of operation

Comparison of different options for harvest of a therapeutic protein product from high cell density yeast fermentation broth

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