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Pastoors J, Baltin C, Bettmer J, Deitert A, Götzen T, Michel C, Deischter J, Schroll I, Biselli A, Palkovits R, Rose M, Jupke A, Büchs J. Respiration-based investigation of adsorbent-bioprocess compatibility. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:49. [PMID: 36934285 PMCID: PMC10024846 DOI: 10.1186/s13068-023-02297-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 03/03/2023] [Indexed: 03/20/2023]
Abstract
BACKGROUND The efficiency of downstream processes plays a crucial role in the transition from conventional petrochemical processes to sustainable biotechnological production routes. One promising candidate for product separation from fermentations with low energy demand and high selectivity is the adsorption of the target product on hydrophobic adsorbents. However, only limited knowledge exists about the interaction of these adsorbents and the bioprocess. The bioprocess could possibly be harmed by the release of inhibitory components from the adsorbent surface. Another possibility is co-adsorption of essential nutrients, especially in an in situ application, making these nutrients unavailable to the applied microorganism. RESULTS A test protocol investigating adsorbent-bioprocess compatibility was designed and applied on a variety of adsorbents. Inhibitor release and nutrient adsorption was studied in an isolated manner. Respiratory data recorded by a RAMOS device was used to assess the influence of the adsorbents on the cultivation in three different microbial systems for up to six different adsorbents per system. While no inhibitor release was detected in our investigations, adsorption of different essential nutrients was observed. CONCLUSION The application of adsorption for product recovery from the bioprocess was proven to be generally possible, but nutrient adsorption has to be assessed for each application individually. To account for nutrient adsorption, adsorptive product separation should only be applied after sufficient microbial growth. Moreover, concentrations of co-adsorbed nutrients need to be increased to compensate nutrient loss. The presented protocol enables an investigation of adsorbent-bioprocess compatibility with high-throughput and limited effort.
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Affiliation(s)
- Johannes Pastoors
- AVT - Biochemical Engineering, RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Chris Baltin
- AVT - Biochemical Engineering, RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Jens Bettmer
- AVT - Biochemical Engineering, RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Alexander Deitert
- AVT - Biochemical Engineering, RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Tobias Götzen
- AVT - Biochemical Engineering, RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Carina Michel
- AVT - Biochemical Engineering, RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Jeff Deischter
- ITMC - Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074, Aachen, Germany
| | - Isabel Schroll
- Chemical Technology II, Department of Chemistry, TU Darmstadt, Alarich-Weiss-Straße 8, 64287, Darmstadt, Germany
| | - Andreas Biselli
- AVT - Fluid Process Engineering, RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Regina Palkovits
- ITMC - Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074, Aachen, Germany
| | - Marcus Rose
- Chemical Technology II, Department of Chemistry, TU Darmstadt, Alarich-Weiss-Straße 8, 64287, Darmstadt, Germany
| | - Andreas Jupke
- AVT - Fluid Process Engineering, RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Jochen Büchs
- AVT - Biochemical Engineering, RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany.
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Dinger R, Lattermann C, Flitsch D, Fischer JP, Kosfeld U, Büchs J. Device for respiration activity measurement enables the determination of oxygen transfer rates of microbial cultures in shaken 96-deepwell microtiter plates. Biotechnol Bioeng 2021; 119:881-894. [PMID: 34951007 DOI: 10.1002/bit.28022] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 12/10/2021] [Accepted: 12/10/2021] [Indexed: 11/02/2022]
Abstract
Mini-bioreactors with integrated online monitoring capabilities are well established in the early stages of process development. Mini-bioreactors fulfil the demand for high-throughput-applications and a simultaneous reduction of material costs and total experimental time. One of the most essential online monitored parameters is the oxygen transfer rate (OTR). OTR-monitoring allows fast characterization of bioprocesses and process transfer to larger scales. Currently, OTR-monitoring on a small-scale is limited to shake flasks and 48-well microtiter plates (MTP). Especially, 96-deepwell MTP are used for high-throughput-experiments during early-stage bioprocess development. However, a device for OTR monitoring in 96-deepwell MTP is still not available. To determine OTR values, the measurement of the gas composition in each well of a MTP is necessary. Therefore, a new micro(µ)-scale Transfer rate Online Measurement device (µTOM) was developed. The µTOM includes 96 parallel oxygen-sensitive sensors and a single robust sealing mechanism. Different organisms (Escherichia. coli, Hansenula polymorpha, and Ustilago maydis) were cultivated in the µTOM. The measurement precision for 96 parallel cultivations was 0.21 mmol·L-1·h-1 (pooled standard deviation). In total, a more than 15-fold increase in throughput and an up to a 50-fold decrease in media consumption, compared with the shake flask RAMOS-technology, was achieved using the µTOM for OTR-monitoring. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Robert Dinger
- RWTH Aachen University, Chair of Biochemical Engineering (AVT.BioVT), Forckenbeckstraße 51, 52074, Aachen, Germany
| | | | - David Flitsch
- PyroScience GmbH, Hubertusstraße 35, 52064, Aachen, Germany
| | - Jan P Fischer
- PyroScience GmbH, Hubertusstraße 35, 52064, Aachen, Germany
| | - Udo Kosfeld
- RWTH Aachen University, Chair of Biochemical Engineering (AVT.BioVT), Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Jochen Büchs
- RWTH Aachen University, Chair of Biochemical Engineering (AVT.BioVT), Forckenbeckstraße 51, 52074, Aachen, Germany
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Chopda VR, Holzberg T, Ge X, Folio B, Tolosa M, Kostov Y, Tolosa L, Rao G. Real-time dissolved carbon dioxide monitoring I: Application of a novel in situ sensor for CO 2 monitoring and control. Biotechnol Bioeng 2020; 117:981-991. [PMID: 31840812 PMCID: PMC7079146 DOI: 10.1002/bit.27253] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 12/10/2019] [Accepted: 12/13/2019] [Indexed: 12/21/2022]
Abstract
Dissolved carbon dioxide (dCO2 ) is a well-known critical parameter in bioprocesses due to its significant impact on cell metabolism and on product quality attributes. Processes run at small-scale faces many challenges due to limited options for modular sensors for online monitoring and control. Traditional sensors are bulky, costly, and invasive in nature and do not fit in small-scale systems. In this study, we present the implementation of a novel, rate-based technique for real-time monitoring of dCO2 in bioprocesses. A silicone sampling probe that allows the diffusion of CO2 through its wall was inserted inside a shake flask/bioreactor and then flushed with air to remove the CO2 that had diffused into the probe from the culture broth (sensor was calibrated using air as zero-point calibration). The gas inside the probe was then allowed to recirculate through gas-impermeable tubing to a CO2 monitor. We have shown that by measuring the initial diffusion rate of CO2 into the sampling probe we were able to determine the partial pressure of the dCO2 in the culture. This technique can be readily automated, and measurements can be made in minutes. Demonstration experiments conducted with baker's yeast and Yarrowia lipolytica yeast cells in both shake flasks and mini bioreactors showed that it can monitor dCO2 in real-time. Using the proposed sensor, we successfully implemented a dCO2 -based control scheme, which resulted in significant improvement in process performance.
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Affiliation(s)
- Viki R. Chopda
- Department of Chemical, Biochemical and Environmental Engineering, Center for Advanced Sensor TechnologyUniversity of MarylandBaltimoreMaryland
| | - Timothy Holzberg
- Department of Chemical, Biochemical and Environmental Engineering, Center for Advanced Sensor TechnologyUniversity of MarylandBaltimoreMaryland
| | - Xudong Ge
- Department of Chemical, Biochemical and Environmental Engineering, Center for Advanced Sensor TechnologyUniversity of MarylandBaltimoreMaryland
| | - Brandon Folio
- Department of Chemical, Biochemical and Environmental Engineering, Center for Advanced Sensor TechnologyUniversity of MarylandBaltimoreMaryland
| | - Michael Tolosa
- Department of Chemical, Biochemical and Environmental Engineering, Center for Advanced Sensor TechnologyUniversity of MarylandBaltimoreMaryland
| | - Yordan Kostov
- Department of Chemical, Biochemical and Environmental Engineering, Center for Advanced Sensor TechnologyUniversity of MarylandBaltimoreMaryland
| | - Leah Tolosa
- Department of Chemical, Biochemical and Environmental Engineering, Center for Advanced Sensor TechnologyUniversity of MarylandBaltimoreMaryland
| | - Govind Rao
- Department of Chemical, Biochemical and Environmental Engineering, Center for Advanced Sensor TechnologyUniversity of MarylandBaltimoreMaryland
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Battling S, Wohlers K, Igwe C, Kranz A, Pesch M, Wirtz A, Baumgart M, Büchs J, Bott M. Novel plasmid-free Gluconobacter oxydans strains for production of the natural sweetener 5-ketofructose. Microb Cell Fact 2020; 19:54. [PMID: 32131833 PMCID: PMC7055074 DOI: 10.1186/s12934-020-01310-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 02/17/2020] [Indexed: 12/14/2022] Open
Abstract
Background 5-Ketofructose (5-KF) has recently been identified as a promising non-nutritive natural sweetener. Gluconobacter oxydans strains have been developed that allow efficient production of 5-KF from fructose by plasmid-based expression of the fructose dehydrogenase genes fdhSCL of Gluconobacter japonicus. As plasmid-free strains are preferred for industrial production of food additives, we aimed at the construction of efficient 5-KF production strains with the fdhSCL genes chromosomally integrated. Results For plasmid-free 5-KF production, we selected four sites in the genome of G. oxydans IK003.1 and inserted the fdhSCL genes under control of the strong P264 promoter into each of these sites. All four recombinant strains expressed fdhSCL and oxidized fructose to 5-KF, but site-specific differences were observed suggesting that the genomic vicinity influenced gene expression. For further improvement, a second copy of the fdhSCL genes under control of P264 was inserted into the second-best insertion site to obtain strain IK003.1::fdhSCL2. The 5-KF production rate and the 5-KF yield obtained with this double-integration strain were considerably higher than for the single integration strains and approached the values of IK003.1 with plasmid-based fdhSCL expression. Conclusion We identified four sites in the genome of G. oxydans suitable for expression of heterologous genes and constructed a strain with two genomic copies of the fdhSCL genes enabling efficient plasmid-free 5-KF production. This strain will serve as basis for further metabolic engineering strategies aiming at the use of alternative carbon sources for 5-KF production and for bioprocess optimization.
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Affiliation(s)
- Svenja Battling
- AVT-Biochemical Engineering, RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Karen Wohlers
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Chika Igwe
- AVT-Biochemical Engineering, RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Angela Kranz
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Matthias Pesch
- AVT-Biochemical Engineering, RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Astrid Wirtz
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Meike Baumgart
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Jochen Büchs
- AVT-Biochemical Engineering, RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany.
| | - Michael Bott
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, 52425, Jülich, Germany.
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Investigation of factors influencing oxygen content in Halobacterium salinarum growth medium for improved bacteriorhodopsin production. INTERNATIONAL JOURNAL OF INDUSTRIAL CHEMISTRY 2019. [DOI: 10.1007/s40090-019-0189-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Pfannebecker J, Schiffer-Hetz C, Fröhlich J, Becker B. Culture medium optimization for osmotolerant yeasts by use of a parallel fermenter system and rapid microbiological testing. J Microbiol Methods 2016; 130:14-22. [DOI: 10.1016/j.mimet.2016.08.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 08/18/2016] [Accepted: 08/20/2016] [Indexed: 12/25/2022]
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Quantifying the sensitivity of G. oxydans ATCC 621H and DSM 3504 to osmotic stress triggered by soluble buffers. J Ind Microbiol Biotechnol 2015; 42:585-600. [PMID: 25645092 DOI: 10.1007/s10295-015-1588-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 01/14/2015] [Indexed: 12/12/2022]
Abstract
In Gluconobacter oxydans cultivations on glucose, CaCO3 is typically used as pH-buffer. This buffer, however, has disadvantages: suspended CaCO3 particles make the medium turbid, thereby, obstructing analysis of microbial growth via optical density and scattered light. Upon searching for alternative soluble pH-buffers, bacterial growth and productivity was inhibited most probably due to osmotic stress. Thus, this study investigates in detail the osmotic sensitivity of G. oxydans ATCC 621H and DSM 3504 using the Respiratory Activity MOnitoring System. The tested soluble pH-buffers and other salts attained osmolalities of 0.32-1.19 osmol kg(-1). This study shows that G. oxydans ATCC 621H and DSM 3504 respond quite sensitively to increased osmolality in comparison to other microbial strains of industrial interest. Osmolality values of >0.5 osmol kg(-1) should not be exceeded to avoid inhibition of growth and product formation. This osmolality threshold needs to be considered when working with soluble pH-buffers.
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Stöckmann C, Palmen TG, Schroer K, Kunze G, Gellissen G, Büchs J. Definition of culture conditions for Arxula adeninivorans, a rational basis for studying heterologous gene expression in this dimorphic yeast. ACTA ACUST UNITED AC 2014; 41:965-76. [DOI: 10.1007/s10295-014-1433-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Accepted: 03/06/2014] [Indexed: 10/25/2022]
Abstract
Abstract
The yeast Arxula adeninivorans is considered to be a promising producer of recombinant proteins. However, growth characteristics are poorly investigated and no industrial process has been established yet. Though of vital interest for strain screening and production processes, rationally defined culture conditions remain to be developed. A cultivation system was evolved based on targeted sampling and mathematical analysis of rationally designed small-scale cultivations in shake flasks. The oxygen and carbon dioxide transfer rates were analyzed as conclusive online parameters. Oxygen limitation extended cultivation and led to ethanol formation in cultures supplied with glucose. Cultures were inhibited at pH-values below 2.8. The phosphorus demand was determined as 1.55 g phosphorus per 100 g cell dry weight. Synthetic SYN6 medium with 20 g glucose l−1 was optimized for cultivation in shake flasks by buffering at pH 6.4 with 140 mmol MES l−1. Optimized SYN6 medium and operating conditions provided non-limited cultivations without by-product formation. A maximal specific growth rate of 0.32 h−1 and short fermentations of 15 h were achieved. A pH optimum curve was derived from the oxygen transfer rates of differently buffered cultures, showing maximal growth between pH 2.8 and 6.5. Furthermore, it was shown that the applied medium and cultivation conditions were also suitable for non-limiting growth and product formation of a genetically modified A. adeninivorans strain expressing a heterologous phytase.
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Affiliation(s)
- Christoph Stöckmann
- grid.1957.a 000000010728696X AVT-Biochemical Engineering RWTH Aachen University Worringer Weg 1 52074 Aachen Germany
| | - Thomas G Palmen
- grid.1957.a 000000010728696X AVT-Biochemical Engineering RWTH Aachen University Worringer Weg 1 52074 Aachen Germany
| | - Kirsten Schroer
- grid.1957.a 000000010728696X AVT-Biochemical Engineering RWTH Aachen University Worringer Weg 1 52074 Aachen Germany
- grid.419481.1 0000000115159979 Novartis Institutes for Biomedical Research 4056 Basel Switzerland
| | - Gotthard Kunze
- grid.418934.3 0000000109439907 Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Corrensstraße 3 06466 Gatersleben Germany
| | - Gerd Gellissen
- grid.1957.a 000000010728696X Microbiology and Genetics, Department of Biology IV RWTH Aachen University Worringer Weg 1 52074 Aachen Germany
| | - Jochen Büchs
- grid.1957.a 000000010728696X AVT-Biochemical Engineering RWTH Aachen University Worringer Weg 1 52074 Aachen Germany
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Salehi-Nik N, Amoabediny G, Pouran B, Tabesh H, Shokrgozar MA, Haghighipour N, Khatibi N, Anisi F, Mottaghy K, Zandieh-Doulabi B. Engineering parameters in bioreactor's design: a critical aspect in tissue engineering. BIOMED RESEARCH INTERNATIONAL 2013; 2013:762132. [PMID: 24000327 PMCID: PMC3755438 DOI: 10.1155/2013/762132] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 06/27/2013] [Accepted: 07/01/2013] [Indexed: 12/21/2022]
Abstract
Bioreactors are important inevitable part of any tissue engineering (TE) strategy as they aid the construction of three-dimensional functional tissues. Since the ultimate aim of a bioreactor is to create a biological product, the engineering parameters, for example, internal and external mass transfer, fluid velocity, shear stress, electrical current distribution, and so forth, are worth to be thoroughly investigated. The effects of such engineering parameters on biological cultures have been addressed in only a few preceding studies. Furthermore, it would be highly inefficient to determine the optimal engineering parameters by trial and error method. A solution is provided by emerging modeling and computational tools and by analyzing oxygen, carbon dioxide, and nutrient and metabolism waste material transports, which can simulate and predict the experimental results. Discovering the optimal engineering parameters is crucial not only to reduce the cost and time of experiments, but also to enhance efficacy and functionality of the tissue construct. This review intends to provide an inclusive package of the engineering parameters together with their calculation procedure in addition to the modeling techniques in TE bioreactors.
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Affiliation(s)
- Nasim Salehi-Nik
- Department of Chemical Engineering, Faculty of Engineering, University of Tehran, P.O. Box 11365-4563, Tehran, Iran
- Department of Biomedical Engineering, Research Center for New Technologies in Life Science Engineering, University of Tehran, P.O. Box 14395-1374, Tehran, Iran
| | - Ghassem Amoabediny
- Department of Chemical Engineering, Faculty of Engineering, University of Tehran, P.O. Box 11365-4563, Tehran, Iran
- Department of Biomedical Engineering, Research Center for New Technologies in Life Science Engineering, University of Tehran, P.O. Box 14395-1374, Tehran, Iran
| | - Behdad Pouran
- Department of Chemical Engineering, Faculty of Engineering, University of Tehran, P.O. Box 11365-4563, Tehran, Iran
- Department of Biomedical Engineering, Research Center for New Technologies in Life Science Engineering, University of Tehran, P.O. Box 14395-1374, Tehran, Iran
| | - Hadi Tabesh
- Institute of Physiology, Medical Faculty, RWTH Aachen University, 52074 Aachen, Germany
| | | | - Nooshin Haghighipour
- National Cell Bank, Pasteur Institute of Iran, P.O. Box 1316943551, Tehran, Iran
| | - Nahid Khatibi
- Department of Chemical Engineering, Faculty of Engineering, University of Tehran, P.O. Box 11365-4563, Tehran, Iran
- Department of Biomedical Engineering, Research Center for New Technologies in Life Science Engineering, University of Tehran, P.O. Box 14395-1374, Tehran, Iran
| | - Fatemeh Anisi
- Department of Chemical Engineering, Faculty of Engineering, University of Tehran, P.O. Box 11365-4563, Tehran, Iran
- Department of Biomedical Engineering, Research Center for New Technologies in Life Science Engineering, University of Tehran, P.O. Box 14395-1374, Tehran, Iran
| | - Khosrow Mottaghy
- Institute of Physiology, Medical Faculty, RWTH Aachen University, 52074 Aachen, Germany
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Hansen S, Hariskos I, Luchterhand B, Büchs J. Development of a modified Respiration Activity Monitoring System for accurate and highly resolved measurement of respiration activity in shake flask fermentations. J Biol Eng 2012; 6:11. [PMID: 22901278 PMCID: PMC3490767 DOI: 10.1186/1754-1611-6-11] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 07/26/2012] [Indexed: 11/13/2022] Open
Abstract
Background The Respiration Activity Monitoring System (RAMOS) is an established device to measure on-line the oxygen transfer rate (OTR), thereby, yielding relevant information about metabolic activities of microorganisms and cells during shake flask fermentations. For very fast-growing microbes, however, the RAMOS technique provides too few data points for the OTR. Thus, this current study presents a new model based evaluation method for generating much more data points to enhance the information content and the precision of OTR measurements. Results In cultivations with E.coli BL21 pRSET eYFP-IL6, short diauxic and even triauxic metabolic activities were detected with much more detail compared to the conventional evaluation method. The decline of the OTR during the stop phases during oxygen limitations, which occur when the inlet and outlet valves of the RAMOS flask were closed for calibrating the oxygen sensor, were also detected. These declines reflected a reduced oxygen transfer due to the stop phases. In contrast to the conventional calculation method the new method was almost independent from the number of stop phases chosen in the experiments. Conclusions This new model based evaluation method unveils new peaks of metabolic activity which otherwise would not have been resolved by the conventional RAMOS evaluation method. The new method yields substantially more OTR data points, thereby, enhancing the information content and the precision of the OTR measurements. Furthermore, oxygen limitations can be detected by a decrease of the OTR during the stop phases.
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Affiliation(s)
- Sven Hansen
- AVT, Biochemical Engineering, RWTH Aachen University, Worringerweg 1, Aachen, 52074, Germany.
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Huber R, Roth S, Rahmen N, Büchs J. Utilizing high-throughput experimentation to enhance specific productivity of an E.coli T7 expression system by phosphate limitation. BMC Biotechnol 2011; 11:22. [PMID: 21414195 PMCID: PMC3068942 DOI: 10.1186/1472-6750-11-22] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Accepted: 03/17/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The specific productivity of cultivation processes can be optimized, amongst others, by using genetic engineering of strains, choice of suitable host/vector systems or process optimization (e.g. choosing the right induction time). A further possibility is to reduce biomass buildup in favor of an enhanced product formation, e.g. by limiting secondary substrates in the medium, such as phosphate. However, with conventional techniques (e.g. small scale cultivations in shake flasks), it is very tedious to establish optimal conditions for cell growth and protein expression, as the start of protein expression (induction time) and the degree of phosphate limitation have to be determined in numerous concerted, manually conducted experiments. RESULTS We investigated the effect of different induction times and a concurrent phosphate limitation on the specific productivity of the T7 expression system E.coli BL21(DE3) pRhotHi-2-EcFbFP, which produces the model fluorescence protein EcFbFP upon induction. Therefore, specific online-monitoring tools for small scale cultivations (RAMOS, BioLector) as well as a novel cultivation platform (Robo-Lector) were used for rapid process optimization. The RAMOS system monitored the oxygen transfer rate in shake flasks, whereas the BioLector device allowed to monitor microbial growth and the production of EcFbFP in microtiter plates. The Robo-Lector is a combination of a BioLector and a pipetting robot and can conduct high-throughput experiments fully automated. By using these tools, it was possible to determine the optimal induction time and to increase the specific productivity for EcFbFP from 22% (for unlimited conditions) to 31% of total protein content of the E.coli cells via a phosphate limitation. CONCLUSIONS The results revealed that a phosphate limitation at the right induction time was suitable to redirect the available cellular resources during cultivation to protein expression rather than in biomass production. To our knowledge, such an effect was shown for the first time for an IPTG-inducible expression system. Finally, this finding and the utilization of the introduced high-throughput experimentation approach could help to find new targets to further enhance the production capacity of recombinant E.coli-strains.
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Affiliation(s)
- Robert Huber
- RWTH Aachen University, Worringerweg 1, D-52074 Aachen, Germany.
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Titova MV, Berkovich EA, Reshetnyak OV, Kulichenko IE, Oreshnikov AV, Nosov AM. Respiration activity of suspension cell culture of Polyscias filicifolia bailey, Stephania glabra (Roxb.) miers, and Dioscorea deltoidea wall. APPL BIOCHEM MICRO+ 2011. [DOI: 10.1134/s0003683811010170] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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13
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Bareither R, Pollard D. A review of advanced small-scale parallel bioreactor technology for accelerated process development: current state and future need. Biotechnol Prog 2010; 27:2-14. [PMID: 21312350 DOI: 10.1002/btpr.522] [Citation(s) in RCA: 144] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2010] [Revised: 06/13/2010] [Indexed: 11/10/2022]
Abstract
The pharmaceutical and biotech industries face continued pressure to reduce development costs and accelerate process development. This challenge occurs alongside the need for increased upstream experimentation to support quality by design initiatives and the pursuit of predictive models from systems biology. A small scale system enabling multiple reactions in parallel (n ≥ 20), with automated sampling and integrated to purification, would provide significant improvement (four to fivefold) to development timelines. State of the art attempts to pursue high throughput process development include shake flasks, microfluidic reactors, microtiter plates and small-scale stirred reactors. The limitations of these systems are compared to desired criteria to mimic large scale commercial processes. The comparison shows that significant technological improvement is still required to provide automated solutions that can speed upstream process development.
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Affiliation(s)
- Rachel Bareither
- Biologics New & Enabling Technologies, Biologics Development, Merck Research Laboratories, Merck & Co. Inc., Rahway, NJ 07065, USA
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Suresh S, Srivastava VC, Mishra IM. Critical analysis of engineering aspects of shaken flask bioreactors. Crit Rev Biotechnol 2010; 29:255-78. [PMID: 19929318 DOI: 10.3109/07388550903062314] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Shaking bioreactors are the most frequently used reaction vessels in biotechnology. Since their inception, shaking bioreactors have been playing a significant role in medicine, agriculture, food, environmental, and industrial research. In spite of their huge practical importance, very little is known about the characteristic properties of shaken cultures from an engineering point of view. In this paper, a critical analysis is presented of the mixing characteristics, aeration, mass and heat transfer, power consumption, and suitability for on-line monitoring and control of various environmental and other operating parameters in aerated and anaerobic/anoxic conditions. Aspects of cell damage due to shear stress generated in shaken flask and loss of sterility due to contamination are also discussed.
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Affiliation(s)
- S Suresh
- Department of Chemical Engineering, Indian Institute of Technology Roorkee, Uttarakhand, India
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15
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Development of an unsteady-state model for a biological system in miniaturized bioreactors. Biotechnol Appl Biochem 2009; 54:163-70. [DOI: 10.1042/ba20090141] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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16
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Scheidle M, Klinger J, Büchs J. Combination of On-line pH and Oxygen Transfer Rate Measurement in Shake Flasks by Fiber Optical Technique and Respiration Activity MOnitoring System (RAMOS). SENSORS 2007; 7:3472-3480. [PMID: 28903306 PMCID: PMC3841907 DOI: 10.3390/s7123472] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2007] [Accepted: 12/20/2007] [Indexed: 11/16/2022]
Abstract
Shake flasks are commonly used for process development in biotechnologyindustry. For this purpose a lot of information is required from the growth conditions duringthe fermentation experiments. Therefore, Anderlei et al. developed the RAMOS technology[1, 2], which proviedes on-line oxygen and carbondioxide transfer rates in shake flasks.Besides oxygen consumption, the pH in the medium also plays an important role for thesuccessful cultivation of micro-organisms and for process development. For online pHmeasurement fiber optical methods based on fluorophores are available. Here a combinationof the on-line Oxygen Transfer Rate (OTR) measurements in the RAMOS device with anon-line, fiber optical pH measurement is presented. To demonstrate the application of thecombined measurement techniques, Escherichia coli cultivations were performed and on-line pH measurements were compared with off-line samples. The combination of on-lineOTR and pH measurements gives a lot of information about the cultivation and, therefore, itis a powerful technique for monitoring shake flask experiments as well as for processdevelopment.
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Affiliation(s)
- Marco Scheidle
- Biochemical Engineering, RWTH Aachen University, Sammelbau Biologie, Worringerweg 1, D-52074 Aachen, Germany.
| | - Johannes Klinger
- Biochemical Engineering, RWTH Aachen University, Sammelbau Biologie, Worringerweg 1, D-52074 Aachen, Germany.
| | - Jochen Büchs
- Biochemical Engineering, RWTH Aachen University, Sammelbau Biologie, Worringerweg 1, D-52074 Aachen, Germany.
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