1
|
Kröncke N, Benning R. Influence of Dietary Protein Content on the Nutritional Composition of Mealworm Larvae ( Tenebrio molitor L.). INSECTS 2023; 14:261. [PMID: 36975946 PMCID: PMC10053216 DOI: 10.3390/insects14030261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/28/2023] [Accepted: 03/03/2023] [Indexed: 06/18/2023]
Abstract
The use of insects as livestock feed is becoming increasingly accepted because they provide an important source of protein. The purpose of this study was to investigate the chemical composition of mealworm larvae (Tenebrio molitor L.) reared on a range of diets that differed in nutritional composition. Focus was placed on the influence of dietary protein content on larval protein and amino acid composition. For the experimental diets, wheat bran was chosen as the control substrate. The following types of flour-pea protein, rice protein, sweet lupine, and cassava, as well as potato flakes, were mixed with wheat bran and used as the experimental diets. An analysis of the moisture, protein, and fat content was then carried out for all diets and larvae. Furthermore, the amino acid profile was determined. It was shown that supplementing the feed with pea and rice protein was most suitable in terms of high protein yield in larvae (70.9-74.1% dry weight) with low fat content (20.3-22.8% dry weight). The total amino acid content was highest in larvae that were fed with a mixture of cassava flour and wheat bran (51.7 ± 0.5% dry weight), as well as the highest content of essential amino acids (30.4 ± 0.2% dry weight). Moreover, a weak correlation between larval protein content and diet was identified, yet a stronger influence of dietary fats and carbohydrates on larval composition was found. This research could result in improved formulations of artificial diets for Tenebrio molitor larvae in the future.
Collapse
|
2
|
Ashizawa R, Rubio N, Letcher S, Parkinson A, Dmitruczyk V, Kaplan DL. Entomoculture: A Preliminary Techno-Economic Assessment. Foods 2022; 11:foods11193037. [PMID: 36230118 PMCID: PMC9564176 DOI: 10.3390/foods11193037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 09/07/2022] [Accepted: 09/21/2022] [Indexed: 11/21/2022] Open
Abstract
Cultured meat, or the practice of growing meat from cell culture, has been experiencing rapid advances in research and technology as the field of biotechnology attempts to answer the call to fight climate change and feed a growing global population. A major hurdle for cell-based meat products entering the market in the near-future is their price. The complex production facilities required to make such products will require advanced bioreactor systems, resources such as energy and water, and a skilled labor force, among other factors. The use of insect cells in this process is hypothesized to address some of these costs due to the characteristics that make them more resilient in cell culture when compared to traditional livestock-derived cells. To address the potential for cost savings by utilizing insect cells in the cultivation of protein-enriched foods, here we utilized a techno-economic assessment model. Three different insect cell lines were used in the model. The results indicate that insect cell lines offer potential to significantly reduce the cost per kilogram of cell cultivated meat, along with further opportunities to optimize production processes through technological advances and scaling.
Collapse
Affiliation(s)
- Reina Ashizawa
- Department of Biology, Tufts University, Medford, MA 02155, USA
| | - Natalie Rubio
- Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA
| | - Sophia Letcher
- Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA
| | - Avery Parkinson
- Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA
| | | | - David L. Kaplan
- Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA
- Correspondence:
| |
Collapse
|
3
|
Novel Symbiotic Genome-Scale Model Reveals Wolbachia's Arboviral Pathogen Blocking Mechanism in Aedes aegypti. mBio 2021; 12:e0156321. [PMID: 34634928 PMCID: PMC8515829 DOI: 10.1128/mbio.01563-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Wolbachia are endosymbiont bacteria known to infect arthropods causing different effects, such as cytoplasmic incompatibility and pathogen blocking in Aedes aegypti. Although several Wolbachia strains have been studied, there is little knowledge regarding the relationship between this bacterium and their hosts, particularly on their obligate endosymbiont nature and its pathogen blocking ability. Motivated by the potential applications on disease control, we developed a genome-scale model of two Wolbachia strains: wMel and the strongest Dengue blocking strain known to date: wMelPop. The obtained metabolic reconstructions exhibit an energy metabolism relying mainly on amino acids and lipid transport to support cell growth that is consistent with altered lipid and cholesterol metabolism in Wolbachia-infected mosquitoes. The obtained metabolic reconstruction was then coupled with a reconstructed mosquito model to retrieve a symbiotic genome-scale model accounting for 1,636 genes and 6,408 reactions of the Aedes aegypti-Wolbachia interaction system. Simulation of an arboviral infection in the obtained novel symbiotic model represents a metabolic scenario characterized by pathogen blocking in higher titer Wolbachia strains, showing that pathogen blocking by Wolbachia infection is consistent with competition for lipid and amino acid resources between arbovirus and this endosymbiotic bacteria.
Collapse
|
4
|
Rubio NR, Fish KD, Trimmer BA, Kaplan DL. Possibilities for Engineered Insect Tissue as a Food Source. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2019. [DOI: 10.3389/fsufs.2019.00024] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
|
5
|
Nutritional demands and metabolic characteristics of the DSIR-HA-1179 insect cell line during growth and infection with the Oryctes nudivirus. In Vitro Cell Dev Biol Anim 2017; 53:908-921. [PMID: 29197034 DOI: 10.1007/s11626-017-0206-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 10/10/2017] [Indexed: 12/21/2022]
Abstract
The DSIR-HA-1179 coleopteran cell line has been identified as a susceptible and permissive host for the in vitro replication of the Oryctes nudivirus, which can be used as a biopesticide against the coconut rhinoceros beetle, pest of palms. The major challenge to in vitro large-scale Oryctes nudivirus production is ensuring process economy. This rests, among other requisites, on the use of low-cost culture media tailored to the nutritional and metabolic needs of the cell line, both in uninfected and infected cultures. The aim of the present study was to characterize the nutritional demands and the metabolic characteristics of the DSIR-HA-1179 cell line during growth and subsequent infection with Oryctes nudivirus in the TC-100 culture medium. Serum-supplementation of the culture medium was found to be critical for cell growth, and addition of 10% fetal bovine serum v/v led to a maximum viable cell density (16.8 × 105 cells ml-1) with a population doubling time of 4.2 d. Nutritional and metabolic characterization of the cell line revealed a trend of glucose and glutamine consumption but minimal uptake of other amino acids, negligible production of lactate and ammonia, and the accumulation of alanine, both before and after infection. The monitoring of virus production kinetics showed that the TC-100 culture medium was nutritionally sufficient to give a peak yield of 7.38 × 107 TCID50 ml-1 of OrNV at the 6th day post-infection in attached cultures of DSIR-HA-1179 cells in 25 cm2 T-flasks. Knowledge of the cell line's nutritional demands and virus production kinetics will aid in the formulation of a low-cost culture medium and better process design for large-scale OrNV production in future.
Collapse
|
6
|
Lohr V, Hädicke O, Genzel Y, Jordan I, Büntemeyer H, Klamt S, Reichl U. The avian cell line AGE1.CR.pIX characterized by metabolic flux analysis. BMC Biotechnol 2014; 14:72. [PMID: 25077436 PMCID: PMC4124504 DOI: 10.1186/1472-6750-14-72] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 07/16/2014] [Indexed: 01/10/2023] Open
Abstract
Background In human vaccine manufacturing some pathogens such as Modified Vaccinia Virus Ankara, measles, mumps virus as well as influenza viruses are still produced on primary material derived from embryonated chicken eggs. Processes depending on primary cell culture, however, are difficult to adapt to modern vaccine production. Therefore, we derived previously a continuous suspension cell line, AGE1.CR.pIX, from muscovy duck and established chemically-defined media for virus propagation. Results To better understand vaccine production processes, we developed a stoichiometric model of the central metabolism of AGE1.CR.pIX cells and applied flux variability and metabolic flux analysis. Results were compared to literature dealing with mammalian and insect cell culture metabolism focusing on the question whether cultured avian cells differ in metabolism. Qualitatively, the observed flux distribution of this avian cell line was similar to distributions found for mammalian cell lines (e.g. CHO, MDCK cells). In particular, glucose was catabolized inefficiently and glycolysis and TCA cycle seem to be only weakly connected. Conclusions A distinguishing feature of the avian cell line is that glutaminolysis plays only a minor role in energy generation and production of precursors, resulting in low extracellular ammonia concentrations. This metabolic flux study is the first for a continuous avian cell line. It provides a basis for further metabolic analyses to exploit the biotechnological potential of avian and vertebrate cell lines and to develop specific optimized cell culture processes, e.g. vaccine production processes.
Collapse
Affiliation(s)
- Verena Lohr
- Max Planck Institute for Dynamics of Complex Technical Systems, Sandtorstr, 1, 39106 Magdeburg, Germany.
| | | | | | | | | | | | | |
Collapse
|
7
|
Chou CC. Identification of the pivotal role of glutamate in enhancing insect cell growth using factor analysis. Cytotechnology 2013; 66:853-60. [PMID: 23989940 DOI: 10.1007/s10616-013-9637-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 08/22/2013] [Indexed: 10/26/2022] Open
Abstract
Although the insect cell/baculovirus system is an important expression platform for recombinant protein production, our understanding of insect cell metabolism with respect to enhancing cell growth capability and productivity is still limited. Moreover, different host insect cell lines may have different growth characteristics associated with diverse product yields, which further hampers the elucidation of insect cell metabolism. To address this issue, the growth behaviors and utilization profiles of common metabolites among five cultured insect cell lines (derived from two insect hosts, Spodoptera frugiperda and Spodoptera exigua) were investigated in an attempt to establish a metabolic framework that can interpret the different cell growth behaviors. To analyze the complicated metabolic dataset, factor analysis was introduced to differentiate the crucial metabolic variations among these cells. Factor analysis was used to decompose the metabolic data to obtain the underlying factors with biological meaning that identify glutamate (a metabolic intermediate involved in glutaminolysis) as a key metabolite for insect cell growth. Notably, glutamate was consumed in significant amounts by fast-growing insect cell lines, but it was produced by slow-growing lines. A comparative experiment using cells grown in culture media with and without glutamine (the starting metabolite in glutaminolysis) was conducted to further confirm the pivotal role of glutamate. The factor analysis strategy allowed us to elucidate the underlying structure and inter-correlation between insect cell growth and metabolite utilization to provide some insights into insect cell growth and metabolism, and this strategy can be further extended to large-scale metabolomic analysis.
Collapse
Affiliation(s)
- Cheng-Chung Chou
- Department of Life Science, Institute of Molecular Biology, National Chung Cheng University, Chia-Yi, 62102, Taiwan,
| |
Collapse
|
8
|
Affiliation(s)
- R Bhatia
- Chemical Engineering and Center for Biotechnology and Bioengineering, 300 Technology Drive, University of Pittsburgh, Pittsburgh, PA, 15219, U.S.A
| | | | | | | |
Collapse
|
9
|
Rhiel M, Murhammer DW. The effect of oscillating dissolved oxygen concentrations on the metabolism of a Spodoptera frugiperda IPLB-Sf21-AE clonal isolate. Biotechnol Bioeng 2012; 47:640-50. [PMID: 18623445 DOI: 10.1002/bit.260470605] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The effect of oscillating dissolved oxygen (DO) concentration on the metabolism of a clonal isolate of the Spodoptera frugiperda IPLB-Sf21-AE insect cell line was investigated. Specifically, the effect on cell growth, re- combinant protein synthesis, glucose and glutamine consumption, and lactate accumulation was determined. Prior to conducting the oscillating DO experiments, it was found that the DO concentration could be reduced to 15% air saturation without adversely affecting the growth rate. Under these conditions, glucose and glutamine became depleted as the maximum cell density was reached. The introduction of DO oscillations, that is, cycles consisting of 30 min at 15% DO followed by 30 min of anoxia, significantly altered cell metabolism, including inhibition of cell growth and recombinant protein synthesis. The effect of DO oscillations on glucose consumption was dependent on the experimental conditions. Glucose exhaustion occurred when the DO oscillations contained either an "apparent" anoxia period (nitrogen sparging discontinued upon reaching 0% DO) without pH control or a "true" anoxia period (nitrogen sparging continued throughout anoxia period) with pH control. Glucose consumption was significantly decreased, however, when the cells were exposed to a "true" anoxia period without pH control, that is, low pH inhibited glucose utilization. Glutamine uptake was not significantly affected by DO oscillations. Lactate only accumulated in the oscillating DO runs, a finding consistent with previous results demonstrating that significant lactate accumulation only occurs under DO-limited conditions. (c) 1995 John Wiley & Sons, Inc.
Collapse
Affiliation(s)
- M Rhiel
- 125B Chemistry Building, Department of Chemical and Biochemical Engineering, The University of Iowa, Iowa City, Iowa 52242
| | | |
Collapse
|
10
|
Tsao EI, Mason MR, Cacciuttolo MA, Bowen SH, Folena-Wasserman G. Production of parvovirus B19 vaccine in insect cells co-infected with double baculoviruses. Biotechnol Bioeng 2012; 49:130-8. [PMID: 18623563 DOI: 10.1002/(sici)1097-0290(19960120)49:2<130::aid-bit2>3.0.co;2-r] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Recombinant human parvovirus B19 virus-like particles (VLPs), a candidate vaccine, were produced using the insect cell (Sf-9)-baculovirus (AcNPV) expression system. The synthesis and assembly of the particles in Sf-9 cells are directed by double infections with one recombinant virus (bacVP1) expressing the parvovirus minor viral protein VP1 and a second virus (bacVP2) expressing the major viral protein VP2. Previous animal studies demonstrated that the polypeptide composition of the VLPs strongly affects the elicitation of virus neutralizing antibodies. The key factor controlling the production of an immunologically potent product in bioreactors was identified to be the multiplicity of infection (MOI) of bacVP1 and bacVP2 used for infection. A probabilistic model, which correlates well with the experimental results, was employed to facilitate the selection of MOIs and to provide a better understanding of the baculovirus co-infection process. A novel production process based on secondary infections was developed to ensure product consistency and to simplify large-scale logistics. The effects of other critical process parameters, such as temperature, dissolved oxygen concentration, lactate concentration, cell concentration at infection, and harvest time, were also investigated. (c) 1996 John Wiley & Sons, Inc.
Collapse
Affiliation(s)
- E I Tsao
- Department of Process Cell Culture and Fermentation, Medimmune, Inc., 35 West Watkins Mill Road, Gaithersburg, Maryland 20878
| | | | | | | | | |
Collapse
|
11
|
Doverskog M, Han L, Häggström L. Cystine/cysteine metabolism in cultured Sf9 cells: influence of cell physiology on biosynthesis, amino acid uptake and growth. Cytotechnology 2012; 26:91-102. [PMID: 22358546 DOI: 10.1023/a:1007963003607] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Spodoptera frugiperda (Sf9) insect cells proliferate in a cystine-free medium, with the same growth rate, reaching the same final cell density, as in a cystine-containing medium, provided that the inoculum is taken from a pre-culture sufficiently early, at 47-53 h. With an inoculum from a 103 h culture an extended lag phase accompanied by cell death was observed during the first 50 h of cystine-free culture, even though the culture had been adapted to cystine-free conditions for 10 passages. Cystine-free cultures seeded with a 103 h inoculum had lower growth rates and reached lower final cell densities than corresponding cystine-supplied cultures. Cysteine biosynthesis occurs from methionine via the β-cystathionine pathway. More methionine was consumed by the cells in cystine-free media, and cystathionine was secreted when methionine and cystine were supplied in excess. The data suggest that cysteine biosynthesis is up-regulated in proliferating cells but down-regulated when the cells enter the stationary phase.In cultures supplied with cystine (10-100 mg 1(-1)), the specific uptake rate and total consumption of cystine, as well as the uptake of glutamate, glutamine and glucose increased with increasing cystine concentrations. These results are interpreted in view of system x (c) (-) , a concentration dependent amino acid transporter. Similarly, the consumption of amino acids transported by system L (ile, leu, val, tyr) was enhanced in cystine-containing cultures, as compared to cystine-free cultures. Uptake of cystine, methionine and system L amino acids ceases abruptly in all cultures, even before growth ceased. The specific growth rate starts to decline early during the growth phase, but this growth behaviour could not be correlated to the depletion of nutrients. We therefore propose that the observed growth pattern is a result of (auto)regulatory events that control both proliferation and metabolism.
Collapse
Affiliation(s)
- M Doverskog
- Department of Biochemistry and Biotechnology, Royal Institute of Technology, S-100 44, Stockholm, Sweden
| | | | | |
Collapse
|
12
|
Ohki T, Mikhailenko SV, Arai T, Ishii S, Ishiwata S. Improvement of the yields of recombinant actin and myosin V–HMM in the insect cell/baculovirus system by the addition of nutrients to the high-density cell culture. J Muscle Res Cell Motil 2012; 33:351-8. [DOI: 10.1007/s10974-012-9323-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 09/04/2012] [Indexed: 10/27/2022]
|
13
|
Drugmand JC, Schneider YJ, Agathos SN. Insect cells as factories for biomanufacturing. Biotechnol Adv 2012; 30:1140-57. [DOI: 10.1016/j.biotechadv.2011.09.014] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Revised: 09/13/2011] [Accepted: 09/16/2011] [Indexed: 10/17/2022]
|
14
|
Moraes AM, Jorge SAC, Astray RM, Suazo CAT, Calderón Riquelme CE, Augusto EFP, Tonso A, Pamboukian MM, Piccoli RAM, Barral MF, Pereira CA. Drosophila melanogaster S2 cells for expression of heterologous genes: From gene cloning to bioprocess development. Biotechnol Adv 2011; 30:613-28. [PMID: 22079894 DOI: 10.1016/j.biotechadv.2011.10.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Revised: 10/07/2011] [Accepted: 10/30/2011] [Indexed: 12/16/2022]
Abstract
In the present review we discuss strategies that have been used for heterologous gene expression in Drosophila melanogaster Schneider 2 (S2) cells using plasmid vectors. Since the growth of S2 cells is not dependent on anchorage to solid substrates, these cells can be easily cultured in suspension in large volumes. The factors that most affect the growth and gene expression of S2 cells, namely cell line, cell passage, inoculum concentration, culture medium, temperature, dissolved oxygen concentration, pH, hydrodynamic forces and toxic metabolites, are discussed by comparison with other insect and mammalian cells. Gene expression, cell metabolism, culture medium formulation and parameters involved in cellular respiration are particularly emphasized. The experience of the authors with the successful expression of a biologically functional protein, the rabies virus glycoprotein (RVGP), by recombinant S2 cells is presented in the topics covered.
Collapse
Affiliation(s)
- Angela M Moraes
- Departamento de Engenharia de Materiais e de Bioprocessos, Faculdade de Engenharia Química, Universidade Estadual de Campinas, Campinas, Brazil.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Bonarius HP, Houtman JH, Schmid G, de Gooijer CD, Tramper J. Metabolic-flux analysis of hybridoma cells under oxidative and reductive stress using mass balances. Cytotechnology 2011; 32:97-107. [PMID: 19002972 DOI: 10.1023/a:1008142218103] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Hybridoma cells were grown at steady state under both reductiveand oxidative stress and the intracellular fluxes weredetermined by mass-balancing techniques. By decreasing the dissolved oxygen pressure (pO(2)) in the bioreactor, the reduced formof nicotinamide adenine nucleotide (NADH) was enhanced relativeto the oxidized form (NAD(+)). Oxidative stress, as a resultof which the NAP(P)(+)/NAD(P)H-ratio increases, was generatedby both the enhancement of the pO(2) to 100% air saturationand by the addition of the artificial electron acceptorphenazine methosulphate (PMS) to the culture medium. It wasfound that fluxes of dehydrogenase reactions by which NAD(P)H isproduced decreased under hypoxic conditions. For example, thedegradation rates of arginine, isoleucine, lysine and theglutamate dehydrogenase flux were significantly lower at oxygenlimitation, and increased at higher pO(2) levels and when PMSwas added to the culture medium. In contrast, the prolinesynthesis reaction, which requires NADPH, decreased under PMSstress. The flux of the NADH-requiring lactate dehydrogenase reaction also strongly decreased from 19 to 3,4 pmol/cell/day,under oxygen limitation and under PMS stress, respectively. Thedata show that metabolic-flux balancing can be used to determinehow mammalian respond to oxidative and reduction stress.
Collapse
Affiliation(s)
- H P Bonarius
- Department PRF-Biotechnology, Hoffman-La Roche Ltd., Bldg. 66/112, CH-4002, Basel, Switzerland
| | | | | | | | | |
Collapse
|
16
|
Kamen AA, Bédard C, Tom R, Perret S, Jardin B. On-line monitoring of respiration in recombinant-baculovirus infected and uninfected insect cell bioreactor cultures. Biotechnol Bioeng 2009; 50:36-48. [PMID: 18626897 DOI: 10.1002/(sici)1097-0290(19960405)50:1<36::aid-bit5>3.0.co;2-2] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Respiration rates in Spodoptera frugiperda (Sf-9) cell bioreactor cultures were successfully measured on-line using two methods: The O(2) uptake rate (OUR) was determined using gas phase pO(2) values imposed by a dissolved oxygen controller and the CO(2) evolution rate (CER) was measured using an infrared detector. The measurement methods were accurate, reliable, and relatively inexpensive. The CER was routinely determined in bioreactor cultures used for the production of several recombinant proteins. Simple linear relationships between viable cell densities and both OUR and CER in exponentially growing cultures were used to predict viable cell density. Respiration measurements were also used to follow the progress of baculoviral infections in Sf-9 cultures. Infection led to increases in volumetric and per-cell respiration rates. The relationships between respiration and several other culture parameters, including viable cell density, cell protein, cell volume, glucose consumption, lactate production, viral titer, and recombinant beta-galactosidase accumulation, were examined. The extent of the increase in CER following infection and the time postinfection at which maximum CER was attained were negatively correlated with the multiplicity of infection (MOI) at multiplicities below the level required to infect all the cells in a culture. Delays in the respiration peak related to the MOI employed were correlated with delays in the peak in recombinant protein accumulation. DO levels in the range 5-100% did not exert any major effects on viable cell densities, CER, or product titer in cultures infected with a baculovirus expressing recombinant beta-galactosidase.
Collapse
Affiliation(s)
- A A Kamen
- Animal Cell Engineering Group, Biotechnology Research Institute, National Research Council Canada, 6100 Royalmount Avenue, Montréal, Québec, Canada
| | | | | | | | | |
Collapse
|
17
|
Bernal V, Carinhas N, Yokomizo AY, Carrondo MJT, Alves PM. Cell density effect in the baculovirus-insect cells system: a quantitative analysis of energetic metabolism. Biotechnol Bioeng 2009; 104:162-80. [PMID: 19459142 DOI: 10.1002/bit.22364] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The cell density effect (i.e., the drop in the specific productivity in the baculovirus-insect cells expression system when cells are infected at high cell densities) has been extensively described in the literature. In this article, a model for the central metabolism of serum-free suspension cultures of Spodoptera frugiperda Sf9 cells is proposed and used to investigate the metabolic basis for this phenomenon. The main metabolic pathways (glycolysis, pentose phosphate pathway, tricarboxylic acids cycle, glutaminolysis, and amino acids metabolism), cellular growth and energetics were considered. The analysis of the stoichiometric model allowed further understanding of the interplay of the consumption of carbon and nitrogen sources in insect cells. Moreover, metabolic flux analysis revealed that Sf9 cells undergo a progressive inhibition of central metabolism when grown to high cell densities, for which the incorporation of amino acids carbon backbones into the TCA cycle (mainly glutamine) and the down-regulation of glycolysis are partially responsible. Following infection by baculovirus and cellular division arrest, central energy metabolism depended on the infection strategy chosen (cell concentration at the moment of infection and multiplicity of infection), inhibition being observed at high cell densities. Interestingly, the energetic status of the culture correlated with the decrease in cellular production of baculovirus, meaning that there is room for process optimization through the application of metabolic engineering techniques.
Collapse
Affiliation(s)
- Vicente Bernal
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa (ITQB-UNL/IBET), Oeiras, Portugal
| | | | | | | | | |
Collapse
|
18
|
Kinetic response of a Drosophila melanogaster cell line to different medium formulations and culture conditions. Cytotechnology 2008; 57:23-35. [PMID: 19003169 DOI: 10.1007/s10616-008-9146-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2007] [Accepted: 03/29/2008] [Indexed: 10/22/2022] Open
Abstract
In the past few years, Drosophila melanogaster cells have been employed for recombinant protein production purposes, and a comprehensive knowledge of their metabolism is essential for process optimization. In this work, the kinetic response of a Schneider S2 cell line, grown in shake flasks, in two different culture media, the serum-free SF900-II((R)) and the serum-supplemented TC-100, was evaluated. Cell growth, amino acids and glucose uptake, and lactate synthesis were measured allowing the calculation of kinetic parameters. The results show that S2 cells metabolism was able to adjust to different environmental situations, as determined by medium formulation, as well as by the particular situation resulting from the culture conditions. Cells attained a 163% higher final cell concentration (1.4 x 10(7) cells mL(-1)) in SF900 II((R)) medium, when compared to serum-supplemented TC-100 medium. Also, a maximum specific cell growth rate 52% higher in SF900 II((R) )medium, when compared to serum-supplemented TC-100 one, was observed. Glutamine was the growth limiting factor in SF900 II((R)) medium, while glucose, sometimes associated with glutamine, controlled growth in serum-supplemented TC-100 medium based formulation. The different pattern of lactate production is an example of the versatility of the metabolism of these cells. This by-product was produced only in glutamine limitation, but the amount synthesized depended not only on the excess glucose, but on other medium components. Therefore, in serum-supplemented TC-100 medium a much smaller lactate amount was generated. Besides, glucose was identified not only as a growth limiting factor, but also as a viability limiting factor, since its depletion accelerated cell death.
Collapse
|
19
|
Gioria VV, Jäger V, Claus JD. Growth, metabolism and baculovirus production in suspension cultures of an Anticarsia gemmatalis cell line. Cytotechnology 2007; 52:113-24. [PMID: 19002870 DOI: 10.1007/s10616-006-9042-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2006] [Accepted: 12/22/2006] [Indexed: 11/26/2022] Open
Abstract
The UFL-AG-286 cell line, established from embryonic tissue of the lepidopteran insect Anticarsia gemmatalis, has been identified as a good candidate to be used as a cellular substrate in the development of a process for in vitro production of the Anticarsia gemmatalis multicapsid nucleopolyhedrovirus, a baculovirus widely used as bioinsecticide. In order to characterize the technological properties of this cell line and evaluate its feasibility to use it for the large-scale production of Anticarsia gemmatalis multicapsid nucleopolyhedrovirus, UFL-AG-286 cells were adapted to grow as agitated suspension cultures in spinner-flasks. Batch suspension cultures of adapted cells in serum-supplemented TC-100 medium grew with a doubling time of about 29 h and reached a maximum cell density higher than 3.5 x 10(6) viable cells ml(-1). At the end of the growth period glucose was completely depleted from the culture medium, but L: -lactate was not produced. Amino acids, with the exception of glutamine, were only negligibly consumed or produced. In contrast to other insect cell lines, UFL-AG-286 cells appeared to be unable to synthesize alanine as a metabolic way to dispose the by-product ammonia. The synchronous infection of suspension cultures with Anticarsia gemmatalis multicapsid nucleopolyhedrovirus in the early to medium exponential growth phase yielded high amounts of both viral progenies per cell and reduced the specific demands of UFL-AG-286 cells for the main nutrients.
Collapse
Affiliation(s)
- Verónica Viviana Gioria
- Laboratorio de Virología, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, CC 242, S3000ZAA, Santa Fe, República Argentina
| | | | | |
Collapse
|
20
|
Jardin BA, Montes J, Lanthier S, Tran R, Elias C. High cell density fed batch and perfusion processes for stable non-viral expression of secreted alkaline phosphatase (SEAP) using insect cells: Comparison to a batch Sf-9-BEV system. Biotechnol Bioeng 2007; 97:332-45. [PMID: 17054119 DOI: 10.1002/bit.21224] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The development of insect cells expressing recombinant proteins in a stable continuous manner is an attractive alternative to the BEV system for recombinant protein production. High cell density fed batch and continuous perfusion processes can be designed to maximize the productivity of stably transformed cells. A cell line (Sf-9SEAP) expressing high levels of the reporter protein SEAP stably was obtained by lipid-mediated transfection of Sf-9 insect cells and further selection and screening. The expression of the Sf-9SEAP cells was compared with the BEVS system. It was observed that, the yield obtained in BEVS was similar to the batch Sf-9SEAP at 8 and 7 IU/mL, respectively. The productivity of this foreign gene product with the stable cells was enhanced by bioprocess intensification employing the fed-batch and perfusion modes of culture to increase the cell density in culture. The fed batch process yielded a maximum cell density of 28 x 10(6) cells/mL and 12 IU/mL of SEAP. Further improvements in the productivity could be made using the perfusion process, which demonstrated a stable production rate for extended periods of time. The process was maintained for 43 days, with a steady-state cell density of 17-20 x 10(6) cells/mL and 7 IU/mL SEAP. The total yield obtained in the perfusion process (394 IU) was approximately 22 and 8 times higher than that obtained in a batch (17.6 IU) and fed batch (46.1 IU) process, respectively.
Collapse
Affiliation(s)
- Barbara Ann Jardin
- Biotechnology Research Institute, National Research Council Canada, 6100 Royalmount Avenue Montreal, Quebec, Canada H4P2R2
| | | | | | | | | |
Collapse
|
21
|
Abstract
Lepidopteran insect cell culture technology has progressed to the point of becoming an essential part of one of the most successful eukaryotic expression systems and is increasingly used industrially on a large scale. Therefore, there is a constant need for convenient and low-cost culture media capable of supporting good insect cell growth and ensuring high yield of baculovirus as well as the strong expression of recombinant proteins. Vertebrate sera or invertebrate hemolymph were essential supplements in first-generation insect cell media. These supplements, however, are cumbersome and expensive for routine large-scale culture; thus, their use is now circumvented by substituting the essential growth factors present in these supplements with serum-free substances. Such non-serum supplements are typically of non-animal origin and include protein hydrolysates, lipid emulsions, and specialized substances (e.g., surfactants and shear damage protecting chemicals). These supplements need to complement the defined, synthetic basal medium to ensure that the fundamental nutritional needs of the cells are satisfied. Although there is a significant number of proprietary serum-free and low-protein or protein-free media on the market, the lack of information concerning their detailed composition is a drawback in their adoption for different applications, including their adaptation to the metabolic and kinetic analysis and monitoring of a given insect cell based bioprocess. Hence, there is wide appeal for formulating serum-free media based on a rational assessment of the metabolic requirements of the lepidopteran cells during both the growth and the production phases. Techniques such as statistical experimental design and genetic algorithms adapted to the cellular behavior and the bioreactor operation mode (batch, fed-batch, or perfusion) permit the formulation of versatile serum- and protein-free media. These techniques are illustrated with recent developments of serum-free media for the cultivation of commercially important Spodoptera frugiperda and Trichoplusia ni cell lines.
Collapse
Affiliation(s)
- Spiros N Agathos
- Unit of Bioengineering, University of Louvain, Louvain-la-Neuve, Belgium
| |
Collapse
|
22
|
Marteijn RCL, Jurrius O, Dhont J, de Gooijer CD, Tramper J, Martens DE. Optimization of a feed medium for fed-batch culture of insect cells using a genetic algorithm. Biotechnol Bioeng 2003; 81:269-78. [PMID: 12474249 DOI: 10.1002/bit.10465] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Insect cells have been cultured for over 30 years, but their application is still hampered by low cell densities in batch fermentations and expensive culture media. With respect to the culture method, the fed-batch culture mode is often found to give the best yields. However, optimization of the feed composition is usually a laborious task. In this report, the successful use of genetic algorithms (GAs) to optimize the growth of insect cells is described. A feed was developed from 11 different medium components, each used at a wide range of concentrations. The feed was optimized within four sets of 20 experiments. The optimized feed was tested in bioreactors and the addition scheme was further improved. The viable-cell density of HzAm1 (Helicoverpa zea) insect cells improved 550% to 19.5 x 10(6) cells/mL compared to a control fermentation in an optimized commercial medium. No accumulation of waste products was found, and none of the amino acids was depleted. Glucose was depleted, which suggests that even further improvement is possible. We show that GAs are a successful method to optimize a complex fermentation in a relatively short time frame and without the need of detailed information concerning the cellular physiology or metabolism.
Collapse
Affiliation(s)
- R C L Marteijn
- Wageningen University, Department of Agrotechnology and Food Sciences, Food and Bioprocess Engineering Group, P.O. Box 8129, 6700 EV, Wageningen, The Netherlands.
| | | | | | | | | | | |
Collapse
|
23
|
Sico C, White S, Tsao E, Varma A. Enhanced kinetic extraction of parvovirus B19 structural proteins. Biotechnol Bioeng 2002; 80:250-6. [PMID: 12226856 DOI: 10.1002/bit.10509] [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] [Indexed: 11/09/2022]
Abstract
Recombinant structural proteins (VP1 and VP2) of the human parvovirus B19 have been expressed simultaneously using the baculovirus expression system to form virus-like particles (VLPs) that have potential use as vaccines. In this study, we report optimization of extraction conditions to recover these VLPs from cell paste. Under hypotonic conditions with neutral pH these VLPs were poorly extracted (up to 3% extraction). Addition of reducing agents, detergents, salts, and sonication did not improve the extractability. While screening for conditions to improve the extractability of the VLPs, we discovered that a combination of higher pH and elevated processing temperature significantly increased the extraction. Whereas increasing pH alone increased extractability from 3% to 6% (pH increased from 8.0 to 9.5), the effect of elevated temperature was much more substantial. At 50 degrees C, we observed the extraction to be more than fivefold higher than that at room temperature (up to 25% extracted at pH 9.0). The kinetics of extraction at elevated temperatures showed a rapid initial rate of extraction (on the order of minutes) followed by a plateau. In addition, we compared the extraction of VP1 expressed alone. VP1 expressed alone is incapable of forming VLPs. We observed that non-VLP VP1 was easily extractable (up to 60% extracted) under conditions in which the VP1 + VP2 VLPs were not extractable. From these studies we conclude that parvovirus B19 structural proteins expressed to form VLPs have a hindered extractability as compared with non-VLP protein. This hindrance to extraction can be significantly reduced by processing at elevated temperatures and an increased pH, possibly due to the enhanced rates of solubilization and diffusion.
Collapse
Affiliation(s)
- Colleen Sico
- MedImmune, Inc., 35 West Watkins Mill Road, Gaithersburg, Maryland 20878, USA
| | | | | | | |
Collapse
|
24
|
Maranga L, Cruz PE, Aunins JG, Carrondo MJT. Production of core and virus-like particles with baculovirus infected insect cells. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2002; 74:183-206. [PMID: 11991179 DOI: 10.1007/3-540-45736-4_9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
In this paper the fundamental aspects of process development for the production of core and virus-like particles with baculovirus infected insect cells are reviewed. The issues addressed include: particle formation and monomer composition, chemical and physical conditions for optimal cell growth, baculovirus replication and product expression, multiplicity of infection strategy, and scale-up of the process. Study of the differences in the metabolic requirements of infected and non-infected cells is necessary for high cell density processes. In the bioreactor, the specific oxygen uptake rate (OURsp) plays a central role in process scale-up, leading to the specification of the bioreactor operational parameters. Shear stress can also be an important variable for bioreactor operation due to its influence on cell growth and product expression. The determination of the critical variables in process development is discussed, showing the relevance of the mathematical models that have been developed for the insect cells/baculovirus system in process implementation and control.
Collapse
Affiliation(s)
- Luis Maranga
- Instituto de Biologia Experimental e Tecnológica/Instituto de Tecnologia Química e Biológica IBET/ITQB, Oeiras, Portugal
| | | | | | | |
Collapse
|
25
|
|
26
|
Schügerl K. Development of bioreaction engineering. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2001; 70:41-76. [PMID: 11092128 DOI: 10.1007/3-540-44965-5_3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
In addition to summarizing the early investigations in bioreaction engineering, the present short review covers the development of the field in the last 50 years. A brief overview of the progress of the fundamentals is presented in the first part of this article and the key issues of bioreaction engineering are advanced in its second part.
Collapse
Affiliation(s)
- K Schügerl
- Institute for Technical Chemistry, University of Hannover, Germany.
| |
Collapse
|
27
|
Abstract
The paper gives a review on the recent development of bioprocess engineering. It includes monitoring of product formation processes by flow injection analysis, various types of chromatographic and spectroscopic methods as well as by biosensors. The evaluation of mycelial morphology and physiology by digital image analysis is discussed also. It deals with advanced control of indirectly evaluated process variables by means of state estimation/observer, with the use of structured and hybrid models, expert systems and pattern recognition for process optimization and gives a short report on the state of the art of metabolic flux analysis and metabolic engineering.
Collapse
Affiliation(s)
- K Schügerl
- Institut für Technische Chemie der Universität Hannover, Callinstr. 3, D-30167, Hannover, Germany.
| |
Collapse
|
28
|
Sugiura T, Amann E. Properties of two insect cell lines useful for the baculovirus expression system in serum-free culture. Biotechnol Bioeng 2000; 51:494-9. [DOI: 10.1002/(sici)1097-0290(19960820)51:4<494::aid-bit13>3.0.co;2-i] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
29
|
Drews M, Doverskog M, Ohman L, Chapman BE, Jacobsson U, Kuchel PW, Häggström L. Pathways of glutamine metabolism in Spodoptera frugiperda (Sf9) insect cells: evidence for the presence of the nitrogen assimilation system, and a metabolic switch by 1H/15N NMR. J Biotechnol 2000; 78:23-37. [PMID: 10702908 DOI: 10.1016/s0168-1656(99)00231-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
1H/15N and 13C NMR were used to investigate metabolism in Spodoptera frugiperda (Sf9) cells. Labelled substrates ([2-15N]glutamine, [5-15N]glutamine, [2-15N]glutamate, 15NH4Cl, [2-15N]alanine, and [1-13C]glucose) were added to batch cultures and the concentration of labelled excreted metabolites (alanine, NH4+, glutamine, glycerol, and lactate) were quantified. Cultures with excess glucose and glutamine produce alanine as the main metabolic by-product while no ammonium ions are released. 1H/15N NMR data showed that both the amide and amine-nitrogen of glutamine was incorporated into alanine in these cultures. The amide-nitrogen of glutamine was not transferred to the amine-position in glutamate (for further transamination to alanine) via free NH4+ but directly via an azaserine inhibitable amido-transfer reaction. In glutamine-free media 15NH4+ was consumed and incorporated into alanine. 15NH4+ was also incorporated into the amide-position of glutamine synthesised by the cells. These data suggest that the nitrogen assimilation system, glutamine synthetase/glutamate synthase (NADH-GOGAT), is active in glutamine-deprived cells. In cultures devoid of glucose, ammonium is the main metabolic by-product while no alanine is formed. The ammonium ions stem both from the amide and amine-nitrogen of glutamine, most likely via glutaminase and glutamate dehydrogenase. 13C NMR revealed that the [1-13C] label from glucose appeared in glycerol, alanine, lactate, and in extracellular glutamine. Labelling data also showed that intermediates of the tricarboxylic acid cycle were recycled to glycolysis and that carbon sources, other than glucose-derived acetylCoA, entered the cycle. Furthermore, Sf9 cell cultures excreted significant amounts glycerol (1.9-3.2 mM) and ethanol (6 mM), thus highlighting the importance of sinks for reducing equivalents in maintaining the cytosolic redox balance.
Collapse
Affiliation(s)
- M Drews
- Department of Biotechnology, Royal Institute of Technology, Stockholm, Sweden
| | | | | | | | | | | | | |
Collapse
|
30
|
Cruz PE, Martins PC, Alves PM, Peixoto CC, Santos H, Moreira JL, Carrondo MJ. Proteolytic activity in infected and noninfected insect cells: degradation of HIV-1 Pr55gag particles. Biotechnol Bioeng 1999; 65:133-43. [PMID: 10458733 DOI: 10.1002/(sici)1097-0290(19991020)65:2<133::aid-bit2>3.0.co;2-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In this work the proteolytic activity in the supernatant and inside insect cells in culture was evaluated for different multiplicities of infection (MOI) and times of infection (TOI). Several methods to detect proteolytic activity in insect cells were tested and that using fluorescein thiocyanite-casein as a substrate was chosen. It was observed that infection caused not only a reduction in the concentration of proteases by decreasing their synthesis but also an inhibition of the intracellular proteolytic activity by increasing the intracellular ATP level (measured by in vivo nuclear magnetic resonance, NMR). The maximum proteolytic activity in the supernatant was observed at 72 hpi except when the cells were infected in the late exponential growth phase or with very low MOI, yielding a nonsynchronous infection. The proteolytic degradation of Pr55gag particles was studied during culture and after harvest. In this particular case it was concluded that the supernatant should be stored at low temperature or quickly purified, since the degradation after 24 h is only 3% at 4 degrees C while at 27 degrees C this value rises to 23%. There is a complex relationship between MOI, TOI, proteolytic activity, and product titer and quality. Thus, the optimal conditions for each case will be a compromise between the final product titer, the desired product quality, and operational issues like process time and capacity, requiring proper integration between bioreaction and downstream processing.
Collapse
Affiliation(s)
- P E Cruz
- Instituto de Biologia Experimental e Tecnológica/Instituto de Tecnologia Química e Biológica, IBET/ITQB, Apartado 12, P-2780 Oeiras, Portugal
| | | | | | | | | | | | | |
Collapse
|
31
|
Mendonça RZ, Palomares LA, Ramı́rez OT. An insight into insect cell metabolism through selective nutrient manipulation. J Biotechnol 1999. [DOI: 10.1016/s0168-1656(99)00094-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
32
|
Abstract
Mass spectrometry in combination with tracer experiments based on 13C substrates can serve as a powerful tool for the modeling and analysis of intracellular fluxes and the investigation of biochemical networks. The theoretical background for the application of mass spectrometry to metabolic flux analysis is discussed. Mass spectrometry methods are especially useful to determine mass distribution of metabolites. Additional information gained from fragmentation of metabolites, e.g., by electron impact ionization, allows further localization of labeling positions, up to complete resolution of isotopomer pools. To effectively handle mass distributions in simulation experiments, a matrix based general methodology is formulated. The natural isotope distribution of carbon, oxygen, hydrogen and nitrogen in the target metabolites is considered by introduction of correction matrices. It is shown by simulation results for the central carbon metabolism that neglecting natural isotope distributions causes significant errors in intracellular flux distributions. By varying relative fluxes into pentosephosphate pathway and pyruvate carboxylation reaction, marked changes in the mass distributions of metabolites result, which are illustrated for pyruvate, oxaloacetate, and alpha-ketoglutarate. In addition mass distributions of metabolites are significantly influenced over a broad range by the degree of reversibility of transaldolase and transketolase reactions in the pentosephosphate pathway. The mass distribution of metabolites is very sensitive towards intracellular flux patterns and can be measured with high accuracy by routine mass spectrometry methods. Copyright 1999 John Wiley & Sons, Inc.
Collapse
Affiliation(s)
- C Wittmann
- Institute of Technical Biochemistry, University of the Saarland, P.O. Box 151150, D-66041 Saarbruecken, Germany
| | | |
Collapse
|
33
|
Zhu Y, Rinzema A, Bonarius H, Tramper J, Bol J. Microbial transglutaminase production by Streptoverticillium mobaraense: analysis of amino acid metabolism using mass balances. Enzyme Microb Technol 1998. [DOI: 10.1016/s0141-0229(98)00034-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
34
|
Abstract
The physiology of cultured animal cells, in particular hybridoma, myeloma and insect cells, with respect to growth and proliferation, amino acid metabolism, energy metabolism and cellular responses to environmental stress is discussed in this paper. The rate of proliferation of hybridoma cells in serum-containing media is limited by growth factors at a surprisingly early stage of growth. To maintain exponential growth in a batch culture, it is necessary to stimulate cell proliferation with repeated additions of serum or pure growth factor. It is further suggested that proliferation of Spodoptera frugiperda (Sf9 insect cells), a normal cell line able to grow in a serum-free medium without any added growth factors, is regulated by autocrine growth factors and possibly by other regulatory mechanisms, as Sf9 cells secrete a growth factor (IGF-I) and the medium still appears nutritionally sufficient at the time of cessation of growth. The uptake and metabolism of amino acids is one of the determinants of growth and production. Wasteful overproduction of amino acids in myeloma and hybridoma cells is a result of excess glutamine, and can be avoided by glutamine limitation. Synthesis of amino acids may be conditional, as in Sf9 cells which synthesise glutamine provided that ammonium is supplied to the medium; and cysteine (from methionine) provided that a sufficiently young inoculum is used. Uptake of amino acids in Sf9 cells appears regulated in relation to the proliferative status as there is a distinct cessation of uptake even before growth ceases. The energy metabolism in myeloma, hybridoma and insect cells is a typically substrate-concentration-dependent overflow metabolism. Substrate limitation (glucose and glutamine) decreases by-product formation and increases metabolic efficiency in all these cell lines. However, glutamine limitation, as used in fed-batch cultures (or chemostat cultures) provokes cell death (in parallel to growth) in hybridoma cells in the concentration range below 0.05 mM.
Collapse
Affiliation(s)
- M Doverskog
- Department of Biochemistry and Biotechnology, Royal Institute of Technology, Stockholm, Sweden
| | | | | | | |
Collapse
|
35
|
Rhiel M, Mitchell-Logean CM, Murhammer DW. Comparison ofTrichoplusia ni BTI-Tn-5B1-4 (high five™) andSpodoptera frugiperda Sf-9 insect cell line metabolism in suspension cultures. Biotechnol Bioeng 1997; 55:909-20. [DOI: 10.1002/(sici)1097-0290(19970920)55:6<909::aid-bit8>3.0.co;2-k] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
36
|
Jin S, Ye K, Shimizu K. Metabolic flux distributions in recombinant Saccharomyces cerevisiae during foreign protein production. J Biotechnol 1997; 54:161-74. [PMID: 9208486 DOI: 10.1016/s0168-1656(97)01694-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A stoichiometric flux balancing analysis was applied to the recombinant yeast cultivation to examine the cellular physiology and relationship between the production of heterologous protein and metabolic fluxes. The fluxes in the metabolic pathway within a recombinant S. cerevisiae grown on galactose alone or mixtures of galactose and ethanol medium were calculated. It is found that an amplification of the PP (Pentose Phosphate) pathway activity resulted in an improvement of the foreign protein expression and cell yield on ATP. The carbon source used for biosynthesis from TCA cycle in the exponential growth phase was 2 and 5-fold higher, respectively, as compared with that in the late exponential growth phase and stationary phase in batch culture with galactose minimum medium. The metabolism of ethanol together with galactose in the recombinant cell looks like increasing the flux from Acetyl-CoA to TCA cycle, and amplifying the flux directing the synthesis of various kinds of precursors such as amino acids and nucleic acid which are necessary for production of a foreign protein. Metabolic flux distribution analysis also shows that the ATP synthesis rate under substrate-level phosphorylation in the mixed carbon source cultivation was lower than that in the sole carbon source (galactose) during the expression of foreign protein. However, the total ATP production rate was higher in the mixed carbon source cultivation.
Collapse
Affiliation(s)
- S Jin
- Department of Biochemical Engineering and Science, Kyushu Institute of Technology, Fukuoka, Japan
| | | | | |
Collapse
|
37
|
�hman L, Alarcon M, Ljunggren J, Ramqvist AK, H�ggstr�m L. Glutamine is not an essential amino acid for Sf-9 insect cells. Biotechnol Lett 1996. [DOI: 10.1007/bf00127885] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
38
|
Bonarius HPJ, Hatzimanikatis V, Meesters KPH, de Gooijer CD, Schmid G, Tramper J. Metabolic flux analysis of hybridoma cells in different culture media using mass balances. Biotechnol Bioeng 1996; 50:299-318. [DOI: 10.1002/(sici)1097-0290(19960505)50:3<299::aid-bit9>3.0.co;2-b] [Citation(s) in RCA: 201] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
39
|
Akhnoukh R, Kretzmer G, Schügerl K. On-line monitoring and control of the cultivation of Spodoptera frugiperda Sf9 insect cells and β-galactosidase production by Autographa californica virus vector. Enzyme Microb Technol 1996. [DOI: 10.1016/0141-0229(95)00093-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
40
|
Raghunand N, Dale BE. Effects of glucose, glutamine, and malate on the metabolism of spodoptera frugiperda clone 9 (sf9) cells. Appl Biochem Biotechnol 1996. [DOI: 10.1007/bf02787867] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
41
|
|
42
|
Ohman L, Ljunggren J, Häggström L. Induction of a metabolic switch in insect cells by substrate-limited fed batch cultures. Appl Microbiol Biotechnol 1995; 43:1006-13. [PMID: 8590651 DOI: 10.1007/bf00166917] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Insect cell metabolism was studied in substrate-limited fed batch cultures of Spodoptera frugiperda (Sf-9) cells. Results from a glucose-limited culture, a glutamine-limited culture, a culture limited in both glucose and glutamine, and a batch culture were compared. A stringent relation between glucose excess and alanine formation was found. In contrast, glucose limitation induced ammonium formation, while, at the same time, alanine formation was completely suppressed. Simultaneous glucose and glucosamine limitation suppressed both alanine and ammonium formation. Although the metabolism was influenced by substrate limitation, the specific growth rate was similar in all cultures. Alanine formation must involve incorporation of free ammonium, if ammonium formation is mediated by glutaminase and glutamate dehydrogenase, as our data suggest. On the basis of the results, two possible pathways for the formation of alanine in the intermediary metabolism are suggested. The cellular yield on glucose was increased 6.6 times during glucose limitation, independently of the cellular yield on glutamine, which was increased 50-100 times during glutamine limitation. The results indicate that alanine overflow metabolism is energetically wasteful and that glutamine is a dispensable amino acid for cultured Sf-9 cells. Preliminary data confirm that glutamine can be synthesized by the cells themselves in amounts sufficient to support growth.
Collapse
Affiliation(s)
- L Ohman
- Department of Biochemistry and Biotechnology, Royal Institute of Technology, Stockholm, Sweden
| | | | | |
Collapse
|
43
|
Drews M, Paalme T, Vilu R. The growth and nutrient utilization of the insect cell line Spodoptera frugiperda Sf9 in batch and continuous culture. J Biotechnol 1995. [DOI: 10.1016/0168-1656(95)00045-r] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
44
|
Hensler W, Singh V, Agathos SN. Sf9 insect cell growth and beta-galactosidase production in serum and serum-free media. Ann N Y Acad Sci 1994; 745:149-66. [PMID: 7832505 DOI: 10.1111/j.1749-6632.1994.tb44370.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- W Hensler
- Schering Plough Research Institute, Union, New Jersey 07083
| | | | | |
Collapse
|
45
|
|
46
|
Abstract
Currently, insect and plant cell cultures are not widely used to make products of commercial interest, largely because the development of large-scale cultivation methods is still in its infancy. With the advances made over the past year, some of the limitations associated with scale-up of these two types of expression system have been addressed. Increasing the oxygen supply and the concentration of various nutrients supplied to insect cells after infection has enabled high specific protein production to be maintained to higher cell densities than ever before, improving overall volumetric yields. Detailed work has focused on the capacity of insect cells to carry out complex post-translational modifications; however, as yet, evidence is conflicting as to the extent of protein processing and complex glycosylation possible in infected cells. In plant cell culture, the accepted axioms concerning large-scale culture have been re-examined. Recent studies have assessed culture at high cell densities and the constraints in reactor design resulting from the 'shear sensitivity' of plant cells. Results show that, as cell densities increase, alterations occur in the pathways of secondary metabolism, leading to decreases in specific productivity. The use of nutrient supplements and a medium cycling strategy shows promise for increasing and sustaining product formation. Furthermore, the importance of dissolved gas composition has been clearly demonstrated by use of a gas recirculation reactor. Reports of taxol and vindoline production in vitro demonstrate the potential and the necessity for further research in scale-up of plant cell culture.
Collapse
Affiliation(s)
- R A Taticek
- School of Chemical Engineering, Cornell University, Ithaca, New York 14853-5201
| | | | | |
Collapse
|
47
|
Wong TK, Nielsen LK, Greenfield PF, Reid S. Relationship between oxygen uptake rate and time of infection of Sf9 insect cells infected with a recombinant baculovirus. Cytotechnology 1994; 15:157-67. [PMID: 7765927 DOI: 10.1007/bf00762390] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Oxygen uptake rates (OUR) of Sf9 insect cells propagated in a serum-free medium (SF900II, Gibco) and of cells infected with a recombinant AcNPV were investigated before and after infection in a laboratory-scale bioreactor. The volumetric OURs of uninfected and exponentially growing cells were found to be proportional to the cell density. For infected cultures, the specific OUR of cells increased immediately after addition of virus and a maximum of 1.3 times the value of uninfected cells was noted for all the cultures between 8 to 30 hours post infection, which coincides with the period at which most viral replication and the majority of DNA synthesis takes place. It was observed that the rate of rise in the specific OUR decreased as the cell density at the time of infection increased, which meant that the later the infection, the later the maximum sOUR was observed. We therefore suggest that OUR measurement can be used to reflect the efficiency of a batch infection. Carbohydrate and amino acid consumption rates from an infected run were analysed in an effort to identify substrate(s) that may be used at increased rates to fuel the rise in oxygen demand observed early in the infection cycle. No observable rise in the consumption rates of glucose or glutamine, which are the major energy sources for animal cells, were seen after infection but an increase in the consumption rates of some amino acids suggests that infected Sf9 cells may utilise amino acids at an enhanced rate for energy post infection.
Collapse
Affiliation(s)
- T K Wong
- Department of Chemical Engineering, University of Queensland, Australia
| | | | | | | |
Collapse
|