The Experts below are selected from a list of 162 Experts worldwide ranked by ideXlab platform
Claude-gilles Dussap - One of the best experts on this subject based on the ideXlab platform.
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Analysis of a continuous culture of Fibrobacter succinogenes S85 on a standardized glucose medium
Bioprocess and Biosystems Engineering, 2010Co-Authors: E. Guiavarch, G. Christophe, Catherine Creuly, A. Pons, Claude-gilles DussapAbstract:Continuous cultures of Fibrobacter succinogenes S85 were performed on a standardized fully synthetic culture medium with glucose as carbon source at a dilution rate ( D = 0.02 h^−1) in a 5-L bioreactor. The culture was stabilized during 20 days and demonstrated the ability of Fibrobacter succinogenes to grow in this synthetic medium. CO_2 partial pressure and redox potential probes were used to check the anaerobic state of the culture. The biomass yield was calculated 0.206 g (g glucose)^−1 and the production yield of succinate, the major end-product, was 0.63 mol (mol glucose)^−1. The consistency of the experimental data was checked by proton and mass (C, N) balances. The results were satisfactory (90–110% recovery) leading to derive a Stoichiometric Equation representative of the growth on glucose. The Stoichiometric coefficients were calculated using data reconciliation and linear algebra methods enabling to obtain a complete modeling of all conversion yields possible.
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Application of a Data Reconciliation Method to the Stoichiometric Analysis of Fibrobacter succinogenes Growth
Applied Biochemistry and Biotechnology, 2008Co-Authors: E. Guiavarch, Catherine Creuly, Agnes Pons, Claude-gilles DussapAbstract:Fibrobacter succinogenes S85, a strictly anaerobic Gram-negative bacterium, was grown in continuous culture in a bioreactor at different dilution rates (0.02 to 0.092 h^−1) on a fully synthetic culture medium with glucose as carbon source. Glucose and ammonium sulfate consumption, as well as biomass, succinate, acetate, formate, and carbohydrate production were regularly measured. The relevant biomass elemental compositions were established for each dilution rate. Robustness of the experimental information was checked by C and N mass balances estimation, which were satisfactory. A detailed overall stoichiometry analysis of the process, including all substrates and products of the culture, was proposed. Online and off-line parameters measured during the culture brought a large number of data which were weighted by their respective variance associated to the measured value. The material balance resulted in an overdetermined linear system of Equations made of weighted relationships including experimental data, elemental balances (C, H, O, N, S, Na), and an additional constraint. The mass balances involved in Stoichiometric Equations were solved using data reconciliation and linear algebra methods to take into account error measurements. This methodology allowed to establish the overall Stoichiometric Equation for each dilution rate studied.
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Evidence for the occurrence of an oxygen limitation during soil bioremediation by solid-state fermentation
Biochemical Engineering Journal, 2002Co-Authors: Julien Troquet, Christian Larroche, Claude-gilles DussapAbstract:Abstract Bioremediation methods are a promising way of dealing with soil and subsoil contamination by organic substances. This biodegradation process is supported by micro-organisms which use the organic carbon from the pollutants as energy source and cells building blocks. The scope of this work is to study the main parameters of the process and the physical limiting steps. Several ground samples from an actual petroleum hydrocarbon contaminated site have been tested. Four fixed bed column reactors and one rotating fermentor are used, enabling the study of the influence of different operating variables on the biodegradation kinetics. The Stoichiometric Equation for bacteria growth and pollutant degradation has been established, allowing the determination of mass balances. Biodegradation monitoring is achieved by continuously measuring the emissions of carbon dioxide. Biodegradation rates and pollution load decrease in the two kinds of bioreactors are also compared.
Daniel I C Wang - One of the best experts on this subject based on the ideXlab platform.
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fed batch cultivation of animal cells using different medium design concepts and feeding strategies
Biotechnology and Bioengineering, 1994Co-Authors: Daniel I C WangAbstract:: In animal cell cultivation, cell density and product concentration are often low due to the accumulation of toxic end-products such as ammonia and lactate and/or the depletion of essential nutrients. A hybridoma cell line (CRL-1606) was cultivated in T-flasks using a newly devised medium feeding strategy. The goals were to decrease ammonia and lactate formation by the design of an initial medium which would provide a starting environment to achieve optimal cell growth. This was followed by using a Stoichiometric Equation governing animal cell growth and then designing a supplemental medium for feeding strategy used to control the nutritional environment. The relationship between the Stoichiometric demands for glutamine and nonessential amino acids was also studied. Through Stoichiometric feeding, nutrient concentrations were controlled reasonably well. Consequently, the specific production rate of lactate was decreased by fourfold compared with conventional fed-batch culture and by 26-fold compared with conventional batch culture. The specific production rate of ammonia was decreased by tenfold compared with conventional fed-batch culture and by 50-fold compared with conventional batch culture. Most importantly, total cell density and monoclonal antibody concentration were increased by five- and tenfold respectively, compared with conventional batch culture. (c) 1994 John Wiley & Sons, Inc.
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Stoichiometric analysis of animal cell growth and its application in medium design
Biotechnology and Bioengineering, 1994Co-Authors: Liangzhi Xie, Daniel I C WangAbstract:Abstract Animal cell cultivation in vitro has been studied for more than 40 years. However, the culture medium composition has not been designed on the basis of the Stoichiometric nutritional demands for animal cell growth. In this article, a model was developed to study the Stoichiometric demands for nutrients (including glucose, 20 amino acids, and 10 vitamins)for the synthesis of cell mass and product. The coefficients for these nutrients in the Stoichiometric Equation governing animal cell growth were determined based on cell composition. In addition, a detailed analysis of the nutrients' roles in the synthesis of cell mass and product was also performed. Applications of the Stoichiometric analysis in animal cell cultivation, such as culture medium design, supplemental medium formulation, and feeding strategy will also be discussed. The Stoichiometric analysis can be potentially employed to analyze results from animal cell cultures, to improve the performance of culture processes, and to design new process rationally. It can also help to provide a better understanding of animal cell metabolism. Simplifications on the cellular energy metabolism were made in order to simplify the model and to provide the preliminary bases to test the process performance. However, this could introduce inaccuracies for the model and results in errors in the calculations of glucose and glutamine concentrations when employed in medium design. (c) 1994 John Wiley & Sons, Inc.
Nagamany Nirmalakhandan - One of the best experts on this subject based on the ideXlab platform.
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a generic Stoichiometric Equation for microalgae microorganism nexus by using clarified domestic wastewater as growth medium
Desalination and Water Treatment, 2013Co-Authors: Maung Thein Myint, Abbas Ghassemi, Nagamany NirmalakhandanAbstract:AbstractStoichiometric Equations for microalgae–microorganism nexus culture were established by using 18 sets of experimental data from the literature where clarified domestic wastewater (CDWW) was used as a growth media. The best correlations between observed and calculated coefficients in the Equations were 0.908, 0.878, 0.838, and 0.849 for reactors R1, R2, R3, and the sum of three reactors, respectively. Then, each Stoichiometric Equation was generalized to quantitatively describe the reactions in each set of data for 18 different experimental conditions. By analysis, the most and second most sensitive limiting parameters were identified from the 18 Stoichiometric Equations. The formulas and Equations were further upgraded to a generic form for a general organic growth medium (CaHbOcNdPf). Microalgae–microorganism nexus was established by using the developed coefficients to depict the limited and balanced reactions. The study showed that nitrogen and phosphorus are required as additives in CDWW in ord...
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A generic Stoichiometric Equation for microalgae–microorganism nexus by using clarified domestic wastewater as growth medium
Desalination and Water Treatment, 2013Co-Authors: Maung Thein Myint, Abbas Ghassemi, Nagamany NirmalakhandanAbstract:AbstractStoichiometric Equations for microalgae–microorganism nexus culture were established by using 18 sets of experimental data from the literature where clarified domestic wastewater (CDWW) was used as a growth media. The best correlations between observed and calculated coefficients in the Equations were 0.908, 0.878, 0.838, and 0.849 for reactors R1, R2, R3, and the sum of three reactors, respectively. Then, each Stoichiometric Equation was generalized to quantitatively describe the reactions in each set of data for 18 different experimental conditions. By analysis, the most and second most sensitive limiting parameters were identified from the 18 Stoichiometric Equations. The formulas and Equations were further upgraded to a generic form for a general organic growth medium (CaHbOcNdPf). Microalgae–microorganism nexus was established by using the developed coefficients to depict the limited and balanced reactions. The study showed that nitrogen and phosphorus are required as additives in CDWW in ord...
Maung Thein Myint - One of the best experts on this subject based on the ideXlab platform.
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a generic Stoichiometric Equation for microalgae microorganism nexus by using clarified domestic wastewater as growth medium
Desalination and Water Treatment, 2013Co-Authors: Maung Thein Myint, Abbas Ghassemi, Nagamany NirmalakhandanAbstract:AbstractStoichiometric Equations for microalgae–microorganism nexus culture were established by using 18 sets of experimental data from the literature where clarified domestic wastewater (CDWW) was used as a growth media. The best correlations between observed and calculated coefficients in the Equations were 0.908, 0.878, 0.838, and 0.849 for reactors R1, R2, R3, and the sum of three reactors, respectively. Then, each Stoichiometric Equation was generalized to quantitatively describe the reactions in each set of data for 18 different experimental conditions. By analysis, the most and second most sensitive limiting parameters were identified from the 18 Stoichiometric Equations. The formulas and Equations were further upgraded to a generic form for a general organic growth medium (CaHbOcNdPf). Microalgae–microorganism nexus was established by using the developed coefficients to depict the limited and balanced reactions. The study showed that nitrogen and phosphorus are required as additives in CDWW in ord...
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A generic Stoichiometric Equation for microalgae–microorganism nexus by using clarified domestic wastewater as growth medium
Desalination and Water Treatment, 2013Co-Authors: Maung Thein Myint, Abbas Ghassemi, Nagamany NirmalakhandanAbstract:AbstractStoichiometric Equations for microalgae–microorganism nexus culture were established by using 18 sets of experimental data from the literature where clarified domestic wastewater (CDWW) was used as a growth media. The best correlations between observed and calculated coefficients in the Equations were 0.908, 0.878, 0.838, and 0.849 for reactors R1, R2, R3, and the sum of three reactors, respectively. Then, each Stoichiometric Equation was generalized to quantitatively describe the reactions in each set of data for 18 different experimental conditions. By analysis, the most and second most sensitive limiting parameters were identified from the 18 Stoichiometric Equations. The formulas and Equations were further upgraded to a generic form for a general organic growth medium (CaHbOcNdPf). Microalgae–microorganism nexus was established by using the developed coefficients to depict the limited and balanced reactions. The study showed that nitrogen and phosphorus are required as additives in CDWW in ord...
E. Guiavarch - One of the best experts on this subject based on the ideXlab platform.
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Analysis of a continuous culture of Fibrobacter succinogenes S85 on a standardized glucose medium
Bioprocess and Biosystems Engineering, 2010Co-Authors: E. Guiavarch, G. Christophe, Catherine Creuly, A. Pons, Claude-gilles DussapAbstract:Continuous cultures of Fibrobacter succinogenes S85 were performed on a standardized fully synthetic culture medium with glucose as carbon source at a dilution rate ( D = 0.02 h^−1) in a 5-L bioreactor. The culture was stabilized during 20 days and demonstrated the ability of Fibrobacter succinogenes to grow in this synthetic medium. CO_2 partial pressure and redox potential probes were used to check the anaerobic state of the culture. The biomass yield was calculated 0.206 g (g glucose)^−1 and the production yield of succinate, the major end-product, was 0.63 mol (mol glucose)^−1. The consistency of the experimental data was checked by proton and mass (C, N) balances. The results were satisfactory (90–110% recovery) leading to derive a Stoichiometric Equation representative of the growth on glucose. The Stoichiometric coefficients were calculated using data reconciliation and linear algebra methods enabling to obtain a complete modeling of all conversion yields possible.
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Application of a Data Reconciliation Method to the Stoichiometric Analysis of Fibrobacter succinogenes Growth
Applied Biochemistry and Biotechnology, 2008Co-Authors: E. Guiavarch, Catherine Creuly, Agnes Pons, Claude-gilles DussapAbstract:Fibrobacter succinogenes S85, a strictly anaerobic Gram-negative bacterium, was grown in continuous culture in a bioreactor at different dilution rates (0.02 to 0.092 h^−1) on a fully synthetic culture medium with glucose as carbon source. Glucose and ammonium sulfate consumption, as well as biomass, succinate, acetate, formate, and carbohydrate production were regularly measured. The relevant biomass elemental compositions were established for each dilution rate. Robustness of the experimental information was checked by C and N mass balances estimation, which were satisfactory. A detailed overall stoichiometry analysis of the process, including all substrates and products of the culture, was proposed. Online and off-line parameters measured during the culture brought a large number of data which were weighted by their respective variance associated to the measured value. The material balance resulted in an overdetermined linear system of Equations made of weighted relationships including experimental data, elemental balances (C, H, O, N, S, Na), and an additional constraint. The mass balances involved in Stoichiometric Equations were solved using data reconciliation and linear algebra methods to take into account error measurements. This methodology allowed to establish the overall Stoichiometric Equation for each dilution rate studied.