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Ho Nam Chang - One of the best experts on this subject based on the ideXlab platform.
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continuous production of succinic acid using an external membrane Cell Recycle system
Journal of Microbiology and Biotechnology, 2009Co-Authors: Moon Il Kim, Sang Yup Lee, Nag Jong Kim, Longan Shang, Yong Keun Chang, Ho Nam ChangAbstract:Succinic acid was produced by continuous fermentation of Actinobacillus succinogenes sp. 130Z in an external membrane Cell Recycle reactor to improve viable Cell concentration and productivity. Using this system, Cell concentration increased to 16.4 g/l at the dilution rate 0.2 h -1 , up to 3 times higher than that of batch culture, and the volumetric productivity of succinic acid increased up to 6.63 g/I/h at the dilution rate 0.5 h -1 , 5 times higher than that of batch fermentation. However, in the continuous culture using a high dilution rate, operational problems including severe membrane fouling and contamination by lactic acid producer were observed. Another succinic acid producer, Mannheimia succiniciproducens MBEL55E, was also utilized in this system, and the Cell concentration and productivity of succinic acid at the dilution rate of 0.3 h -1 were found to be above 3 and 2.3 times higher, respectively, compared with those obtained at the dilution rate of 0.1 h -1 . These observations give a deep insight into the process design for a continuous succinic acid production by microorganisms.
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High Cell density ethanol fermentation in an upflow packed-bed Cell Recycle bioreactor
Biotechnology and Bioprocess Engineering, 2008Co-Authors: Ho Nam Chang, Jong Won Kang, Chang Moon Jeong, Joong Kon ParkAbstract:An upflow packed-bed Cell Recycle bioreactor (IUPCRB) is proposed for obtaining a high Cell density. The system is comprised of a stirred tank bioreactor in which Cells are retained partially by a packed-bed. A 1.3 cm (ID) × 48 cm long packed-bed was installed inside a 2 L bioreactor (working volume 1 L). Continuous ethanol fermentation was carried out using a 100 g/L glucose solution containing Saccharomyces cerevisiae (ATCC 24858). Cell retention characteristics were investigated by varying the void fraction (VF) of the packed bed by packing it with particles of 0.8∼2.0 mm sized stone, cut hollow fiber pieces, ceramic, and activated carbon particles. The best results were obtained using an activated carbon bed with a VF of 30∼35%. The IUPCRB yielded a maximum Cell density of 87 g/L, an ethanol concentration of 42 g/L, and a productivity of 21 g/L/h when a 0.5 h^−1 dilution rate was used. A natural bleeding of Cells from the filter bed occurred intermittently. This Cell loss consisted of an average of 5% of the Cell concentration in the bioreactor when a high Cell concentration (approximately 80 g/L) was being maintained.
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high rate continuous production of lactic acid by lactobacillus rhamnosus in a two stage membrane Cell Recycle bioreactor
Biotechnology and Bioengineering, 2001Co-Authors: Sunhoon Kwon, Ho Nam Chang, Ik-keun Yoo, Woo Gi Lee, Yong Keun ChangAbstract:It is important to produce L(+)-lactic acid at the lowest cost possible for lactic acid to become a candidate monomer material for promising biodegradable polylactic acid. In an effort to develop a high-rate bioreactor that provides high productivity along with a high concentration of lactic acid, the performance of membrane Cell-Recycle bioreactor (MCRB) was investigated via experimental studies and simulation optimization. Due to greatly increased Cell density, high lactic acid productivity, 21.6 g L(-1) h(-1), was obtained in the reactor. The lactic acid concentration, however, could not be increased higher than 83 g/L. When an additional continuous stirred tank reactor (CSTR) was attached next to the MCRB a higher lactic acid concentration of 87 g/L was produced at significant productivity expense. When the two MCRBs were connected in series, 92 g/L lactic acid could be produced with a productivity of 57 g L(-1) h(-1), the highest productivity among the reports of L(+)-lactic acid that obtained lactic acid concentration higher than 85 g/L using glucose substrate. Additionally, the investigation of lactic acid fermentation kinetics resulted in a successful model that represents the characteristics of lactic acid fermentation by Lactobacillus rhamnosus. The model was found to be applicable to most of the existing data with MCRBs and was in good agreement with Levenspiel's product-inhibition model, and the Luedeking-Piret equation for product-formation kinetics appeared to be effective in representing the fermentation kinetics. There was a distinctive difference in the production potential of Cells (Cell-density-related parameter in Luedeking-Piret equation) as lactic acid concentration increases over 55 g/L, and this finding led to a more precise estimation of bioreactor performance.
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Bacteriorhodopsin production by Cell Recycle culture of Halobacterium halobium
Biotechnology Letters, 1998Co-Authors: Sang Yup Lee, Ho Nam Chang, Soon Ho HongAbstract:When Halobacterium halobium R1 was cultured with Cell Recycle in a bioreactor equipped with an external hollow fiber membrane unit, the Cell and bacteriorhodopsin concentrations reached in 10 days were 30.3 g Cell dry weight/l and 282 mg/l, respectively. The productivity of bacteriorhodopsin (1.15 mg/l·h) was much higher than that (0.16 mg/l·h) obtained by typical batch fermentation. © Rapid Science Ltd. 1998
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High density Cell culture by membrane-based Cell Recycle
Biotechnology advances, 1994Co-Authors: Ho Nam Chang, Ik-keun Yoo, Beom Soo KimAbstract:Enhancement of productivity of a bioprocess necessitates continuous operation of bioreactors with high biomass concentrations than are possible in conventional batch, fedbatch or continuous modes of culture. Membrane-based Cell Recycle has been effectively used to maintain high Cell concentrations in bioreactors. This review compares membranebased Cell Recycle operation with other such high density Cell culture systems as immobilized Cell reactors and reactors with Cell Recycle by centrifugation or gravity sedimentation. A theoretical of production of primary and secondary metabolites in membrane-based Recycle systems is presented. Operation of this type of system is discussed with examples from aerobic and anaerobic fermentations.
Jin-ho Seo - One of the best experts on this subject based on the ideXlab platform.
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Production of xylitol by recombinant Saccharomyces cerevisiae containing xylose reductase gene in repeated fed-batch and Cell-Recycle fermentations
Enzyme and Microbial Technology, 2004Co-Authors: Sun-myung Bae, Jin-ho Choi, Yeon-woo Ryu, Yong-cheol Park, Tae-hee Lee, Do-hyun Kweon, Sung-koo Kim, Jin-ho SeoAbstract:Abstract Xylitol is a well-known sugar substitute with low-calorie and anti-cariogenic characteristics. An effort of biological production of xylitol from xylose was made in repeated fed-batch and Cell-Recycle fermentations of recombinant Saccharomyces cerevisiae BJ3505/δXR harboring the xylose reductase gene from Pichia stipitis . Batch fermentation with 20 g/l xylose and 18 g/l glucose resulted in 9.52 g/l dry Cell mass, 20.1 g/l xylitol concentration and approximately 100% conversion yield. Repeated fed-batch operation to remove 10% of culture broth and to supplement an equal volume of 200 g/l xylose was designed to improve xylitol production. In spite of a sudden drop of Cell concentration, an increase in dry Cell mass led to high accumulation of xylitol at 48.7 g/l. To overcome loss of xylitol-producing biocatalysts in repeated fed-batch fermentation, Cell-Recycle equipment of hollow fiber membrane was implemented into a xylitol production system. Cell-Recycle operation maintained concentration of the recombinant Cells high inside a bioreactor. Final dry Cell mass of 22.0 g/l, 116 g/l xylitol concentration, 2.34 g/l h overall xylitol productivity were obtained in Cell-Recycle fermentation supplemented with xylose and yeast extract solution, which were equivalent to 2.3-, 5.8- and 3.8-fold increases compared with the corresponding values of batch-type xylitol production parameters.
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Production of xylitol in Cell Recycle fermentations of Candida tropicalis
Biotechnology Letters, 2000Co-Authors: Jin-ho Choi, Kwan-hoon Moon, Yeon-woo Ryu, Jin-ho SeoAbstract:Xylitol was produced a in two-substrate, batch fermentation with Cell recycling of Candida tropicalis ATCC 13803. A series of Cell-Recycle experiments showed that the feeding of xylose, glucose and yeast extract in the xylitol production phase was most effective in enhancing xylitol productivity. The optimized Cell Recycle fermentation resulted in 0.82 g xylitol/g xylose yield, 4.94 g xylitol l−1 h−1 productivity, and final xylitol concentration of 189 g l−1. These results were 1.3 times higher in volumetric xylitol productivity and 2.2 times higher in final product concentration compared with the corresponding values of the optimized two-substrate batch culture.
Carole Molina-jouve - One of the best experts on this subject based on the ideXlab platform.
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RTD/IAD parametric study of liquid and biomass phases in a twostage bioreactor with Cell Recycle
2011Co-Authors: Lamia Ben Gaida, Christophe Andre, Carine Bideaux, Sandrine Alfenore, Xavier Cameleyre, Carole Molina-jouve, Luc FillaudeauAbstract:A two-stage continuous bioreactor with Cell Recycle (TSCB) was developed in order to study the behaviour of Saccharomyces cerevisiae in high Cell density. Residence time (RTD) and internal age (IAD) distributions of gas, liquid and Cell biomass phases have been investigated according to a systemic approach (model identification, parametric study) in order to highlight the complex interactions between hydrodynamics (gas, liquid and solid phases) and biological activity. The noticeable differences between liquid and Cell biomass could be explained by the competition between the internal recirculation and dilution rates and described by the dimensionless circulation index, K [3]. A parametric study is reported and discussed. Assumption based on these dimensionless parameters and reduced adaptation time enable to define acceptable and unacceptable working conditions in order to maintain the biological activity of the microorganism (specific rates and viability) as well as identifying optimal working conditions.
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Using tracer experiments to identify hydrodynamic behaviour of a two-stage bioreactor with Cell Recycle
2009Co-Authors: Luc Fillaudeau, Lamia Ben Gaida, Christophe Andre, Carine Bideaux, Sandrine Alfenore, Xavier Cameleyre, Carole Molina-jouveAbstract:Using tracer experiments to identify hydrodynamic behaviour of a two-stage bioreactor with Cell Recycle. 12. Congrès de la Société Française de Génie des Procédés (SFGP 2009) "Pour relever les défis industriels du XXIème siècle
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Liquid and gas residence time distribution in a two-stage bioreactor with Cell Recycle
2008Co-Authors: Lamia Ben Gaida, Christophe Andre, Carine Bideaux, Sandrine Alfenore, Xavier Cameleyre, Carole Molina-jouve, Luc FillaudeauAbstract:Liquid and gas residence time distribution in a two-stage bioreactor with Cell Recycle. Tracer5, Tracers and Tracing methods
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Very high ethanol productivity in an innovative continuous two-stage bioreactor with Cell Recycle
Bioprocess and Biosystems Engineering, 2006Co-Authors: F. Ben Chaabane, Carine Bideaux, Sandrine Alfenore, Xavier Cameleyre, A. Aldiguier, P. Blanc, S. Guillouet, Gilles Roux, Carole Molina-jouveAbstract:The performance of an innovative two-stage continuous bioreactor with Cell Recycle—potentially capable of giving very high ethanol productivity—was investigated. The first stage was dedicated to Cell growth, whereas the second stage was dedicated to ethanol production. A high Cell density was obtained by an ultrafiltration module coupled to the outlet of the second reactor. A Recycle loop from the second stage to the first one was tested to improve Cell viability and activity. Cultivations of Saccharomyces cerevisiae in mineral medium on glucose were performed at 30°C and pH 4. At steady state, total biomass concentrations of 59 and 157 gDCW l−1 and ethanol concentrations of 31 and 65 g l−1 were obtained in the first and second stage, respectively. The residual glucose concentration was 73 g l−1 in the first stage and close to zero in the second stage. The present study shows that a very high ethanol productivity (up to 41 g l−1 h−1) can indeed be obtained with complete conversion of the glucose and with a high ethanol titre (8.3°GL) in the two-stage system.
Yong Keun Chang - One of the best experts on this subject based on the ideXlab platform.
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continuous production of succinic acid using an external membrane Cell Recycle system
Journal of Microbiology and Biotechnology, 2009Co-Authors: Moon Il Kim, Sang Yup Lee, Nag Jong Kim, Longan Shang, Yong Keun Chang, Ho Nam ChangAbstract:Succinic acid was produced by continuous fermentation of Actinobacillus succinogenes sp. 130Z in an external membrane Cell Recycle reactor to improve viable Cell concentration and productivity. Using this system, Cell concentration increased to 16.4 g/l at the dilution rate 0.2 h -1 , up to 3 times higher than that of batch culture, and the volumetric productivity of succinic acid increased up to 6.63 g/I/h at the dilution rate 0.5 h -1 , 5 times higher than that of batch fermentation. However, in the continuous culture using a high dilution rate, operational problems including severe membrane fouling and contamination by lactic acid producer were observed. Another succinic acid producer, Mannheimia succiniciproducens MBEL55E, was also utilized in this system, and the Cell concentration and productivity of succinic acid at the dilution rate of 0.3 h -1 were found to be above 3 and 2.3 times higher, respectively, compared with those obtained at the dilution rate of 0.1 h -1 . These observations give a deep insight into the process design for a continuous succinic acid production by microorganisms.
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high rate continuous production of lactic acid by lactobacillus rhamnosus in a two stage membrane Cell Recycle bioreactor
Biotechnology and Bioengineering, 2001Co-Authors: Sunhoon Kwon, Ho Nam Chang, Ik-keun Yoo, Woo Gi Lee, Yong Keun ChangAbstract:It is important to produce L(+)-lactic acid at the lowest cost possible for lactic acid to become a candidate monomer material for promising biodegradable polylactic acid. In an effort to develop a high-rate bioreactor that provides high productivity along with a high concentration of lactic acid, the performance of membrane Cell-Recycle bioreactor (MCRB) was investigated via experimental studies and simulation optimization. Due to greatly increased Cell density, high lactic acid productivity, 21.6 g L(-1) h(-1), was obtained in the reactor. The lactic acid concentration, however, could not be increased higher than 83 g/L. When an additional continuous stirred tank reactor (CSTR) was attached next to the MCRB a higher lactic acid concentration of 87 g/L was produced at significant productivity expense. When the two MCRBs were connected in series, 92 g/L lactic acid could be produced with a productivity of 57 g L(-1) h(-1), the highest productivity among the reports of L(+)-lactic acid that obtained lactic acid concentration higher than 85 g/L using glucose substrate. Additionally, the investigation of lactic acid fermentation kinetics resulted in a successful model that represents the characteristics of lactic acid fermentation by Lactobacillus rhamnosus. The model was found to be applicable to most of the existing data with MCRBs and was in good agreement with Levenspiel's product-inhibition model, and the Luedeking-Piret equation for product-formation kinetics appeared to be effective in representing the fermentation kinetics. There was a distinctive difference in the production potential of Cells (Cell-density-related parameter in Luedeking-Piret equation) as lactic acid concentration increases over 55 g/L, and this finding led to a more precise estimation of bioreactor performance.
Seung Won Park - One of the best experts on this subject based on the ideXlab platform.
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increase of xylitol productivity by Cell Recycle fermentation of candida tropicalis using submerged membrane bioreactor
Journal of Bioscience and Bioengineering, 2006Co-Authors: Soungyu Kwon, Seung Won ParkAbstract:Candida tropicalis, an osmophilic strain isolated from honeycomb, produced xylitol at a maximal volumetric productivity of 3.5 g l−1 h−1 from an initial xylose concentration of 200 g l−1. Even at a very high xylose concentration, e.g., 350 g l−1, this strain produced xylitol at a moderate rate of 2.07 g l−1 h−1. In a fed-batch fermentation of xylose and glucose, 260 g l−1 xylose was added, and the xylitol production was 234 g l−1 for 48 h, corresponding to a rate of 4.88 g l−1 h−1. To increase xylitol productivity, Cells were Recycled in a submerged membrane bioreactor with suction pressure and air sparging. For each Recycle round in Cell-Recycle fermentation, the average concentration of xylitol produced, fermentation time, volumetric productivity, and product yield were 180 g l−1, 19.5 h, 8.5 g l−1 h−1, and 85%, respectively. When Cell-Recycle fermentation was started with the Cell mass concentrated twofold after batch fermentation and performed for 10 Recycle rounds, we achieved a very high productivity of 12 g l−1 h−1. The productivity and total amount of xylitol in Cell-Recycle fermentation were 3.4- and 11.0-fold higher than those in batch fermentation, respectively.