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Hoffmann A, Zollinger M, Pacios K, Bucsella B, Kalman F. Reversed-phase HPLC based assay for selective and sensitive endotoxin quantification - part II. J Chromatogr A 2024; 1717:464657. [PMID: 38280360 DOI: 10.1016/j.chroma.2024.464657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 01/10/2024] [Accepted: 01/11/2024] [Indexed: 01/29/2024]
Abstract
The impact of naturally occurring 3-deoxy-d-manno‑oct-2-ulsonic acid (Kdo) derivatives on endotoxin (ET) quantification was investigated for six ET standards. In our recently published chemical Kdo-DMB-LC ET assay (Bucsella et al., Anal. Methods, 2020, 12,4621) [1], the rare, ET specific sugar acid Kdo is used for ET quantification of S-type ETs. The ET content is calculated based on an external Kdo standard or a representative ET standard. In absence of a specific ET standard, the calculation is based on the reference standard ET (RSE) structure or on a worst-case scenario. This scenario overestimates the total ET content of typical S-type ET preparations by a factor of four. Mainly R-type ETs contain in addition to Kdo also Kdo-s non-stoichiometrically modified with phosphoethanolamine (PEtN), galactose (Gal) or L‑glycero-d-manno-heptose (Hep) in substantial quantities. These Kdo species are separated from the unmodified Kdo. All Kdo and Kdo species follow an exponential hydrolytic release from the ET core in dependence on the hydrolysis time. Hydrolysis kinetics for identical Kdo species are the same for all ET standards. Kdo-Gal was released fastest followed by unsubstituted Kdo, Kdo-PEtN, and Kdo-Hep. Between 90 and 150 min a plateau of maximum content is obtained for all Kdo-s. That allows in case of a representative ET standard, ET quantification based on the most present Kdo derivative, here mainly unsubstituted Kdo. If no representative ET standard is available Kdo and all Kdo species must be considered for ET quantification. With that the Kdo-DMB-LC assay is applicable for R- and S-type ETs.
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Affiliation(s)
- Anika Hoffmann
- University of Applied Sciences and Arts Western Switzerland Valais, Institute of Life Technologies, Rue de l'Industrie 23, Sion 1950, Switzerland
| | - Mathieu Zollinger
- University of Applied Sciences and Arts Western Switzerland Valais, Institute of Life Technologies, Rue de l'Industrie 23, Sion 1950, Switzerland
| | - Kevin Pacios
- University of Applied Sciences and Arts Western Switzerland Valais, Institute of Life Technologies, Rue de l'Industrie 23, Sion 1950, Switzerland
| | - Blanka Bucsella
- University of Zürich, Department of Chemistry, Winterthurerstr. 190, Zürich 8057, CH, Switzerland
| | - Franka Kalman
- University of Applied Sciences and Arts Western Switzerland Valais, Institute of Life Technologies, Rue de l'Industrie 23, Sion 1950, Switzerland.
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Kiesewetter A, Gupta A, Heinen-Kreuzig A, Greenhalgh T, Stein A. Improved endotoxin removal using ecofriendly detergents for intensified plasmid capture. Biotechnol Prog 2023; 39:e3375. [PMID: 37531318 DOI: 10.1002/btpr.3375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 05/03/2023] [Accepted: 06/27/2023] [Indexed: 08/04/2023]
Abstract
Increasing plasmid demand for both production of viral and gene therapies as well as nucleic acid based vaccines has highlighted bottlenecks in production. One bottleneck is traditional bead-based chromatography as a capture step. To meet the needs of fast-growing markets, new production solutions are needed. These solutions must enable efficient capture of a diverse range of plasmid types and excellent clearance of bacterial host impurities, such as endotoxin. Enhanced endotoxin clearance during chromatographic purification has previously been demonstrated with detergents such as Triton™ X-100. However, degradation products of Triton™ X-100 are known to have a negative environmental impact, and more sustainable, environmentally benign alternatives have been identified. This work establishes an efficient, intensified plasmid capture using convective anion exchange (AEX) chromatography. The feasibility of the intensified capture approach was assessed with different membrane and a monolith AEX supports. Various detergents from different physico-chemical classes were evaluated with different AEX technologies. Purification efficiency evaluated endotoxin and host cell protein (HCP) clearance, plasmid yield, potential interference of the detergents with analytical in-process control assays, and overall process compatibility. This comprehensive screening approach provides valuable insights to intensified plasmid production.
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Affiliation(s)
- André Kiesewetter
- MilliporeSigma, The Life Science Business of Merck KGaA, Darmstadt, Germany
| | - Akshat Gupta
- MilliporeSigma, The Life Science Business of Merck KGaA, Darmstadt, Germany
| | | | - Trish Greenhalgh
- MilliporeSigma, The Life Science Business of Merck KGaA, Darmstadt, Germany
| | - Andreas Stein
- MilliporeSigma, The Life Science Business of Merck KGaA, Darmstadt, Germany
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Hoffmann A, Pacios K, Mühlemann R, Daumke R, Frank B, Kalman F. Application of a novel chemical assay for the quantification of endotoxins in bacterial bioreactor samples. J Chromatogr B Analyt Technol Biomed Life Sci 2023; 1228:123839. [PMID: 37527605 DOI: 10.1016/j.jchromb.2023.123839] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 06/26/2023] [Accepted: 07/19/2023] [Indexed: 08/03/2023]
Abstract
A novel chemical assay, the so-called Kdo-DMB-liquid chromatography (LC) assay, was used for the accurate and cost-effective determination of the endotoxin content in supernatants of Gram-negative bacteria bioreactor samples. During mild acid hydrolysis, the endotoxin-specific sugar acid 3-deoxy-D-manno-oct-2-ulsonic acid (Kdo) is quantitatively released. Kdo is reacted with 1,2-diamino-4,5-methylenedioxybenzene (DMB) to obtain the highly fluorescent derivate Kdo-DMB. It is separated from the reaction mixture by reversed phase-(U)HPLC and detected by fluorescence. From the Kdo content the endotoxin content of the sample is calculated. For three batch cultivations of Escherichia coli K12 and a fed-batch cultivation of Pseudomonas putida KT2440, the evolution of the endotoxin content in dependence on the cultivation time was monitored. Under optimal, constant cultivation conditions a linear correlation between the endotoxin content and the easy-to-access bioreactor parameters optical density at 600 nm and dry cell weight was found for both endotoxin kinds. Under stress cultivation conditions the E. coli K12 cultivation showed a stronger increase of the endotoxin content at harvest in comparison to optimal conditions. Optical density and dry cell weight may be used for production reactors as an economic real-time estimation tool to determine the endotoxin content at different cultivation time points and conditions. The optical density can further be used to establish straightforward sample dilution schemes for endotoxin quantification in samples of unknown endotoxin content. The endotoxin content [ng mL-1] measured by the Kdo-DMB-LC assay and the endotoxin activity [EU mL-1] obtained by the compendial Limulus Amoebocyte Lysate assay show a high correlation for the bacterial bioreactor samples tested.
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Affiliation(s)
- Anika Hoffmann
- University of Applied Sciences and Arts Western Switzerland Valais, Institute of Life Technology, Rue de l'Industrie 23, 1950 Sion, Switzerland
| | - Kevin Pacios
- University of Applied Sciences and Arts Western Switzerland Valais, Institute of Life Technology, Rue de l'Industrie 23, 1950 Sion, Switzerland
| | - Reto Mühlemann
- FILTROX AG, Moosmühlestr. 6, 9000 St. Gallen, Switzerland
| | - Ralph Daumke
- FILTROX AG, Moosmühlestr. 6, 9000 St. Gallen, Switzerland
| | - Brian Frank
- FILTROX AG, Moosmühlestr. 6, 9000 St. Gallen, Switzerland
| | - Franka Kalman
- University of Applied Sciences and Arts Western Switzerland Valais, Institute of Life Technology, Rue de l'Industrie 23, 1950 Sion, Switzerland.
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4
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Jurjevec A, Brocard C, Striedner G, Cserjan-Puschmann M, Hahn R. Polyethyleneimine efficiently extracts recombinant cytoplasmatic green fluorescent protein produced in Escherichia coli with high purity. J Biotechnol 2023:S0168-1656(23)00114-1. [PMID: 37285941 DOI: 10.1016/j.jbiotec.2023.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 05/10/2023] [Accepted: 06/02/2023] [Indexed: 06/09/2023]
Abstract
We used a polycationic polymer polyethyleneimine (PEI) to develop a method to extract recombinant proteins produced in the Escherichia coli (E. coli) cytosol. Compared to high pressure homogenization, commonly used to disrupt E. coli cells, our extraction method leads to higher purity of extracts. Upon addition of PEI to the cells, flocculation occurs and the recombinant protein gradually diffuses out of the PEI/cell network. While several aspects such as the E. coli strain, the cell or PEI concentration as well as the protein titer and the pH of the buffer seem to influence the extraction rate, our results show that the PEI molecule (molecular weight and structure) must be chosen appropriately for protein extraction. The method works well with resuspended cells but can also be applied directly to fermentation broths at higher PEI concentration. This extraction approach allows for effective reduction of DNA, endotoxins, and host cell proteins levels by 2 to 4 orders of magnitude, and drastically facilitate the subsequent downstream processing steps such as centrifugation and filtration.
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Affiliation(s)
- Alexander Jurjevec
- Christian Doppler Laboratory for Production of Next-Level Biopharmaceuticals in E. coli, Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, 1190 Vienna, Austria
| | - Cécile Brocard
- Boehringer Ingelheim RCV GmbH & Co KG, Dr.-Boehringer-Gasse 5-11, A-1120 Wien
| | - Gerald Striedner
- Christian Doppler Laboratory for Production of Next-Level Biopharmaceuticals in E. coli, Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, 1190 Vienna, Austria
| | - Monika Cserjan-Puschmann
- Christian Doppler Laboratory for Production of Next-Level Biopharmaceuticals in E. coli, Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, 1190 Vienna, Austria
| | - Rainer Hahn
- Christian Doppler Laboratory for Production of Next-Level Biopharmaceuticals in E. coli, Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, 1190 Vienna, Austria.
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5
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Rychen G, Aquilina G, Azimonti G, Bampidis V, Bastos MDL, Bories G, Chesson A, Cocconcelli PS, Flachowsky G, Gropp J, Kolar B, Kouba M, López-Alonso M, López Puente S, Mantovani A, Mayo B, Ramos F, Saarela M, Villa RE, Wester P, Costa L, Dierick N, Glandorf B, Herman L, Kärenlampi S, Leng L, Aguilera J, Tarrés-Call J, Wallace RJ. Safety and efficacy of l-arginine produced by fermentation with Escherichia coli NITE BP-02186 for all animal species. EFSA J 2018; 16:e05276. [PMID: 32625913 PMCID: PMC7009537 DOI: 10.2903/j.efsa.2018.5276] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
l-Arginine is considered as a non-essential amino acid for most adult mammalian species, but it is classified as essential for birds, fish, possibly reptiles and also for strict carnivores. l-Arginine produced by fermentation with Escherichia coli NITE BP-02186, genetically modified to enhance the production of l-arginine, is intended to be used in feed and water for drinking for all animal species and categories. The product under assessment does not give rise to any safety concern with regard to the genetic modification of the production strain. Its use as a nutritional additive is safe for target species when supplemented to diets in appropriate amounts. The use of l-arginine as a feed flavouring agent is unlikely to pose any concern. No risks are expected for the consumer from the use of the product under assessment as a feed additive. It is not irritant to skin or eyes, nor a skin sensitiser. Although the presence of endotoxin activity is of no concern, the available exposure and toxicological data indicate that the additive may pose a risk to users by inhalation. The use of this additive in animal nutrition does not pose a risk to the environment. The additive is an effective source of arginine for all species. l-Arginine is considered efficacious when used as a flavouring compound in animal nutrition.
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Wallace RJ, Gropp J, Dierick N, Costa LG, Martelli G, Brantom PG, Bampidis V, Renshaw DW, Leng L. Risks associated with endotoxins in feed additives produced by fermentation. Environ Health 2016; 15:5. [PMID: 26768246 PMCID: PMC4714429 DOI: 10.1186/s12940-016-0087-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 01/10/2016] [Indexed: 05/27/2023]
Abstract
Increasingly, feed additives for livestock, such as amino acids and vitamins, are being produced by Gram-negative bacteria, particularly Escherichia coli. The potential therefore exists for animals, consumers and workers to be exposed to possibly harmful amounts of endotoxin from these products. The aim of this review was to assess the extent of the risk from endotoxins in feed additives and to calculate how such risk can be assessed from the properties of the additive. Livestock are frequently exposed to a relatively high content of endotoxin in the diet: no additional hazard to livestock would be anticipated if the endotoxin concentration of the feed additive falls in the same range as feedstuffs. Consumer exposure will be unaffected by the consumption of food derived from animals receiving endotoxin-containing feed, because the small concentrations of endotoxin absorbed do not accumulate in edible tissues. In contrast, workers processing a dusty additive may be exposed to hazardous amounts of endotoxin even if the endotoxin concentration of the product is low. A calculation method is proposed to compare the potential risk to the worker, based on the dusting potential, the endotoxin concentration and technical guidance of the European Food Safety Authority, with national exposure limits.
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Affiliation(s)
- R John Wallace
- Rowett Institute of Nutrition and Health, University of Aberdeen, Bucksburn, Aberdeen, AB21 9SB, UK.
| | | | - Noël Dierick
- Department of Animal Production, Ghent University, Ghent, Belgium.
| | - Lucio G Costa
- Department of Neuroscience, University of Parma, Parma, Italy.
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA.
| | - Giovanna Martelli
- Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy.
| | | | - Vasileios Bampidis
- Division of Animal Production, Department of Agricultural Technology, School of Agricultural Technology, Food Technology and Nutrition, Alexander Technological Educational Institute (ATEITHE), 57400, Thessaloniki, Greece.
| | | | - Lubomir Leng
- Institute of Animal Physiology, Slovak Academy of Sciences, Kosice, Slovakia.
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Safety of L‐tryptophan produced by fermentation using Escherichia coli CGMCC 3667, for all animal species based on a dossier submitted by GBT Europe GmbH. EFSA J 2016. [DOI: 10.2903/j.efsa.2016.4343] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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8
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Safety of L‐threonine produced by fermentation using Escherichia coli CGMCC 3703, for all animal species based on a dossier submitted by GBT Europe GmbH. EFSA J 2016. [DOI: 10.2903/j.efsa.2016.4344] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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9
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Scientific Opinion on the safety and efficacy of l‐threonine produced by Escherichia coli strains NRRL B‐30843, DSM 26131, KCCM11133P or DSM 25085 for all animal species based on a dossier submitted by AMAC EEIG. EFSA J 2015. [DOI: 10.2903/j.efsa.2015.4236] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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10
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Scientific Opinion on the safety and efficacy of L‐tryptophan, technically pure, produced by Escherichia coli strains DSM 25084, KCCM 11132P or SARI12091203 for all animal species based on a dossier submitted by AMAC EEIG. EFSA J 2015. [DOI: 10.2903/j.efsa.2015.4238] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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11
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Scientific Opinion on the safety and efficacy of l‐lysine monohydrochloride, technically pure, produced with Escherichia coli CGMCC 3705 and l‐lysine sulphate produced with Corynebacterium glutamicum CGMCC 3704 for all animal species, based on a dossier submitted by HELM AG. EFSA J 2015. [DOI: 10.2903/j.efsa.2015.4156] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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12
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Scientific Opinion on the safety and efficacy of l‐lysine sulphate produced by fermentation with Escherichia coli CGMCC 3705 for all animal species. EFSA J 2015. [DOI: 10.2903/j.efsa.2015.4155] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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13
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Scientific Opinion on the safety and efficacy of l‐valine (l‐valine, feed grade) produced by Escherichia coli NITE BP‐01755 for all animal species based on a dossier submitted by Ajinomoto Eurolysine S.A.S. EFSA J 2015. [DOI: 10.2903/j.efsa.2015.4110] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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14
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Programmable bacterial catalysis - designing cells for biosynthesis of value-added compounds. FEBS Lett 2012; 586:2184-90. [DOI: 10.1016/j.febslet.2012.02.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2012] [Revised: 02/16/2012] [Accepted: 02/20/2012] [Indexed: 12/26/2022]
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15
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Hedhammar M, Bramfeldt H, Baris T, Widhe M, Askarieh G, Nordling K, Aulock SV, Johansson J. Sterilized recombinant spider silk fibers of low pyrogenicity. Biomacromolecules 2010; 11:953-9. [PMID: 20235574 DOI: 10.1021/bm9014039] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We have recently shown that it is possible to recombinantly produce a miniature spider silk protein, 4RepCT, that spontaneously self-assembles into mechanically stable macroscopic fibers (Stark, M.; Grip, S.; Rising, A.; Hedhammar, M.; Engstrom, W.; Hjalm, G.; Johansson, J. Macroscopic fibers self-assembled from recombinant miniature spider silk proteins. Biomacromolecules 2007, 8 (5), 1695-1701). When produced as a soluble fusion protein (with thioredoxin) in Escherichia coli , the spider silk protein can be subjected to several purification steps without aggregating. Here, combined purification and endotoxin removal is achieved using a simple cell wash procedure, protein affinity purification, and LPS depletion. No toxic chemicals were included in the process and the protein retained its ability to self-assemble into fibers. With this method, fibers with pyrogenicity corresponding to less than 1 EU/mg could be recovered. Moreover, the fibers could be sterilized through autoclaving with retained morphology, structure, and mechanical properties. This implies that this recombinant silk is suitable for usage as biomaterial, which is further supported by data showing that the fibers allow growth of human primary fibroblasts.
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Affiliation(s)
- My Hedhammar
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala Biomedical Centre, SE-751 23 Uppsala, Sweden.
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16
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Mattiasson B, Teeparuksapun K, Hedström M. Immunochemical binding assays for detection and quantification of trace impurities in biotechnological production. Trends Biotechnol 2009; 28:20-7. [PMID: 19896744 DOI: 10.1016/j.tibtech.2009.10.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Revised: 09/15/2009] [Accepted: 10/08/2009] [Indexed: 11/29/2022]
Abstract
New, highly sensitive, biosensor concepts make it possible to assay biomacromolecules at concentrations that previously were far below the limit of detection. The previous generation of assays used in quality control situations during biotechnological production was designed primarily for monitoring target molecules, which typically appeared in high concentrations. Hence, novel analytical techniques with high sensitivity should become increasingly important in meeting the demands from regulatory agencies with regard to declaring levels of impurities in biopharmaceuticals. Such techniques also open up opportunities for a range of other challenging measurements, for example, in the area of biohazards. This review describes the development of immuno-based biosensors and exemplifies these by presenting analyses of common impurities in biopharmaceutical production.
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Affiliation(s)
- Bo Mattiasson
- Department of Biotechnology, Lund University, P.O. Box 124, SE-22100 Lund, Sweden
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17
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Lara AR, Caspeta L, Gosset G, Bolívar F, Ramírez OT. Utility of an Escherichia coli strain engineered in the substrate uptake system for improved culture performance at high glucose and cell concentrations: an alternative to fed-batch cultures. Biotechnol Bioeng 2008; 99:893-901. [PMID: 17929322 DOI: 10.1002/bit.21664] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Overflow metabolism is an undesirable characteristic of aerobic cultures of Escherichia coli. It results from elevated glucose consumption rates that cause a high substrate conversion to acetate, severely affecting cell physiology and bioprocess performance. Such phenomenon typically occurs in batch cultures under high glucose concentration. Fed-batch culture, where glucose uptake rate is controlled by external addition of glucose, is the classical bioprocessing alternative to prevent overflow metabolism. Despite its wide-spread use, fed-batch mode presents drawbacks that could be overcome by simpler batch cultures at high initial glucose concentration, only if overflow metabolism is effectively prevented. In this study, an E. coli strain (VH32) lacking the phosphoenolpyruvate: carbohydrate phosphotransferase system (PTS) with a modified glucose transport system was cultured at glucose concentrations of up to 100 g/L in batch mode, while expressing the recombinant green fluorescence protein (GFP). At the highest glucose concentration tested, acetate accumulated to a maximum of 13.6 g/L for the parental strain (W3110), whereas a maximum concentration of only 2 g/L was observed for VH32. Consequently, high cell and GFP concentrations of 52 and 8.2 g/L, respectively, were achieved in VH32 cultures at 100 g/L of glucose. In contrast, maximum biomass and GFP in W3110 cultures only reached 65 and 48%, respectively, of the values attained by the engineered strain. A comparison of this culture strategy against traditional fed-batch culture of W3110 is presented. This study shows that high cell and recombinant protein concentrations are attainable in simple batch cultures by circumventing overflow metabolism through metabolic engineering. This represents a novel and valuable alternative to classical bioprocessing approaches.
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Affiliation(s)
- Alvaro R Lara
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, AP 510-3, Morelos 62250, Mexico
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18
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Villadsen J, Patil KR. Optimal fed-batch cultivation when mass transfer becomes limiting. Biotechnol Bioeng 2007; 98:706-10. [PMID: 17421044 DOI: 10.1002/bit.21451] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In the design of an aerobic fed-batch process to produce, for example, a pharmaceutical protein, the volumetric production rate will eventually become limited by mass transfer when the biomass concentration exceeds a certain upper limit x*. It appears to be common practice to switch from exponential feed of substrate to a constant feed rate when x* is reached. This is done to avoid oxygen starvation with a potential risk of undesired stress responses. But with a constant feed rate the carbon source (glucose) concentration may decrease to a low level with a resulting loss of viability and an undesired production of endotoxins. It is shown that an exponential feeding strategy may be continued, but with a smaller exponent than the one used before oxygen limitation occurs. This will diminish the potential detrimental effects on the culture due to low glucose concentration, and the total time to reach a given final biomass concentration will be reduced.
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Affiliation(s)
- John Villadsen
- Department of Chemical Engineering, Technical University of Denmark, 2800 Lyngby, Denmark.
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19
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Svensson M, Svensson I, Enfors SO. Osmotic stability of the cell membrane of Escherichia coli from a temperature-limited fed-batch process. Appl Microbiol Biotechnol 2004; 67:345-50. [PMID: 15856216 DOI: 10.1007/s00253-004-1832-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2004] [Revised: 10/22/2004] [Accepted: 10/23/2004] [Indexed: 11/28/2022]
Abstract
The temperature-limited fed-batch (TLFB) process is a technique where the oxygen consumption rate is controlled by a gradually declining temperature profile rather than a growth-limiting glucose-feeding profile. In Escherichia coli cultures, it has been proven to prevent an extensive release of endotoxins, i.e. lipopolysaccharides, that occurs in the glucose-limited fed-batch (GLFB) processes at specific growth rates below 0.1 h(-1). The TLFB and the GLFB process were compared to each other when applied to produce the periplasmic, constitutively expressed, enzyme beta-lactamase. The extraction of the enzyme was performed by osmotic shock. A higher production of beta-lactamase was achieved with the TLFB technique while no difference in the endotoxin release was found during the extraction procedure. Furthermore, it was found that growth at declining temperature, generated by the TLFB technique, gradually stabilizes the cytoplasmic membrane, resulting in a significantly increased product quality in the extract from the TLFB cultures in the osmotic shock treatment.
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Affiliation(s)
- Marie Svensson
- Department of Biotechnology, Royal Institute of Technology (KTH), Albanova University Centre, S-10691 Stockholm, Sweden
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