The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Jin-ho Seo - One of the best experts on this subject based on the ideXlab platform.
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Controlling the sucrose concentration increases Coenzyme Q10 production in Fed-Batch Culture of Agrobacterium tumefaciens
Applied microbiology and biotechnology, 2007Co-Authors: Sang-yong Kim, Jin-ho Seo, Hee-jung Moon, Kyoung-mi Lee, Jung-kul LeeAbstract:The production yield of Coenzyme Q10 (CoQ10) from the sucrose consumed by Agrobacterium tumefaciens KCCM 10413 decreased, and high levels of exopolysaccharide (EPS) accumulated after switching from Batch Culture to Fed-Batch Culture. Therefore, we examined the effect of sucrose concentration on the fermentation profile by A. tumefaciens. In the continuous Fed-Batch Culture with the sucrose concentration maintained constantly at 10, 20, 30, and 40 g l−1, the dry cell weight (DCW), specific CoQ10 content, CoQ10 production, and the production yield of CoQ10 from the sucrose consumed increased, whereas EPS production decreased as maintained sucrose concentration decreased. The pH-stat Fed-Batch Culture system was adapted for CoQ10 production to minimize the concentration of the carbon source and osmotic stress from sucrose. Using the pH-stat Fed-Batch Culture system, the DCW, specific CoQ10 content, CoQ10 production, and the product yield of CoQ10 from the sucrose consumed increased by 22.6, 13.7, 39.3, and 39.3%, respectively, whereas EPS production decreased by 30.7% compared to those of Fed-Batch Culture in the previous report (Ha SJ, Kim SY, Seo JH, Oh DK, Lee JK, Appl Microbiol Biotechnol, 74:974–980, 2007). The pH-stat Fed-Batch Culture system was scaled up to a pilot scale (300 l), and the CoQ10 production results obtained (626.5 mg l−1 of CoQ10 and 9.25 mg g DCW−1 of specific CoQ10 content) were similar to those obtained at the laboratory scale. Thus, an efficient and highly competitive process for microbial CoQ10 production is available.
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Overproduction of Phytolacca insularis protein in Batch and Fed-Batch Culture of recombinant Escherichia coli
Process Biochemistry, 2001Co-Authors: Dae-hyuk Kweon, Nam Soo Han, Kyungmoon Park, Jin-ho SeoAbstract:Escherichia coli TG1 transformed with an expression plasmid pMS carrying the gene encoding Phytolacca insularis protein (PIP) under the control of the tac promoter was cultivated in various conditions to improve the productivity of PIP. Production of PIP was dramatically increased by the addition of yeast extract as a nitrogen source in both Batch and Fed-Batch Cultures. High levels of PIP were obtained by adopting a Fed-Batch process and an optimized induction strategy. The optimized Fed-Batch Culture resulted in 59.0 g of cell mass and 466.5 mg of soluble PIP per litre of Culture, corresponding to a 9.1 fold increase in cell mass and a 17.3 fold enhancement in PIP production compared with a simple Batch Culture in Luria broth.
Takeshi Kobayashi - One of the best experts on this subject based on the ideXlab platform.
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Growth and kinetic parameters of Ajuga hairy root in Fed-Batch Culture on monosaccharide medium
Journal of Chemical Technology & Biotechnology, 2007Co-Authors: Nobuyuki Uozumi, Katsuhito Kohketsu, Takeshi KobayashiAbstract:The Batch Culture of a transgenic plant, Ajuga hairy root, in sucrose and MS medium exhibited glucose and fructose accumulation with Culture time and depletion of phosphate ion after 16 days. The use of a monosaccharide instead of sucrose in Fed-Batch Culture avoided the difficulty of estimating the concentration of saccharides. Glucose was the most adequate monosaccharide for attaining a high cell mass. In Fed-Batch Culture using a turbine blade fermentor, 27.2 kg-dry cell m−3 was obtained at 39 days in glucose medium, with the final cell mass and production of 20-hydroxyecdysone increasing 2.6-fold and 2.0-fold, respectively, compared with Batch Culture results with sucrose in a shake flask. The growth of the hairy root was divided into two phases, an exponential growth phase and linear growth phase. The linear growth phase from 5 through 25 kg-dry cell m−3 predominated over the growth curve. On the basis of the data of the Fed-Batch Culture with glucose, the cell yield, 0.77 g g−1, and maintenance coefficient, 0.105 g g−1 day−1, for Ajuga hairy root were comparable to those of various calluses. The cell yield of the plant cell was larger than the yields of microorganisms and the maintenance coefficient was smaller.
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lipase production in two step Fed Batch Culture of organic solvent tolerant pseudomonas aeruginosa lst 03
Journal of Bioscience and Bioengineering, 2001Co-Authors: Takeshi Ito, Hirokazu Kikuta, Eiji Nagamori, Hiroyasu Ogino, Haruo Ishikawa, Hiroyuki Honda, Takeshi KobayashiAbstract:Efficient lipase production by two-step Fed-Batch Culture of an organic solvent-tolerant bacterium, Pseudomonas aeruginosa LST-03, was investigated. When FB synthetic medium was used in flask Culture, no lipase activity was detected, whereas lipase was produced at 2.3 I.U./ml in C2 complex medium. However, lipase production was induced in FB medium when a fatty acid was added to the Culture broth in the stationary phase. Among fatty acids tested, long chain saturated fatty acids, such as C18 (stearic acid) and C20 (arachidic acid), were found to function as effective inducers for the production of lipase, giving an activity level almost the same as that obtained in C2 medium in flask Culture. Two-step lipase production, comprised of a growth phase in Fed-Batch mode and a production phase in which lipase was induced by the addition of 5% (v/v) stearic acid, was carried out in a jar-fermentor. In the growth phase, the maximum cell concentration at 16 h was only 20 in terms of the optical density at 660 nm (OD660), and a low level of lipase production (8 I.U./ml) was obtained after 167 h. This was considered to be due to the exhaustion of several medium components brought about by the use of an unsuitable medium or feeding solution. After analyzing the contents of the compounds in the Culture broth by inductively coupled plasma spectrometry for metal ions and HPLC for anions, a modified FB medium was designed. When this modified FB medium was used in two-step Fed-Batch Culture, the maximum cell concentration reached an OD660 of 55 (30.2 g-dry cells/l) at 16.5 h, and lipase was produced at 96 I.U./ml after 35 h, which is approximately 40 times higher than the production level obtained in flask Culture using C2 medium.
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Insecticide production by recombinant Bacillus subtilis 1A96 in Fed-Batch Culture with control of glucose concentration
Journal of Fermentation and Bioengineering, 1993Co-Authors: Chantal Cayuela, Yong Soo Park, Shinji Iijima, Kenichi Kai, Takeshi KobayashiAbstract:Abstract A Fed-Batch Culture of Bacillus subtilis strain 1A96 containing an insecticide gene integrated into the chromosome was performed by controlling glucose concentration at about 2 g/l and 9 g/l. The cell concentration and insecticidal potency obtained at 2 g/l of glucose were 104 g-dry cell/l and 394 kIU/ml, which were 2.2 and 1.6 times, respectively, as high as those of the Fed-Batch Culture with control of glucose concentration at 9 g/l.
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Fed-Batch Culture of hairy root using fructose as a carbon source
Journal of Fermentation and Bioengineering, 1991Co-Authors: Nobuyuki Uozumi, Hiroyuki Honda, Katsuhito Kohketsu, Osamu Kondo, Takeshi KobayashiAbstract:Abstract Repeated-Batch and Fed-Batch Cultures using sucrose or fructose as a carbon source were carried out in a bioreactor to attain a high cell density of carrot hairy root. From the Batch Culture experiment, cell yields for main components in the medium were determined and the composition of the medium was modified. In the case of the repeated-Batch Culture using sucrose, the concentrations of the medium components were kept almost constant and after 40 d the final cell mass increased two-fold, i.e. 19 g-dry weight/l compared with the Batch Culture. In the Fed-Batch Culture using sucrose, 17 g-dry weight/l of the hairy root was obtained after 48 d by keeping the conductivity of the Culture medium constant. Although the concentrations of the medium components including sucrose were kept almost constant, it was found that fructose and glucose accumulated in the Culture medium up to 30 g/l. This accumulation could be avoided by using a monosaccharide, e.g. fructose in a Fed-Batch Culture, and the final biomass concentration reached 30.1 g-dry weight/l after 38 d. This study shows that the plant cell density in the bioreactor can be greatly improved by feeding with a monosaccharide as the carbon source in Fed-Batch Culture.
Eun-ki Kim - One of the best experts on this subject based on the ideXlab platform.
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Production and characterization of low molecular weight sophorolipid under Fed-Batch Culture.
Bioresource Technology, 2013Co-Authors: Vivek Kumar Morya, Sanggui Jeon, Ji-ho Park, Tae Jung Kim, Eun-ki KimAbstract:The present study was designed for the production and optimization of the C12-C14 sophorolipid, using the yeast Candida bombicola ATCC-22214. The fermentation was carried under Fed-Batch Culture conditions i.e., maintaining 15% coconut oil and 10% glucose as hydrophobic and hydrophilic carbon sources, respectively. A maximum yield 54.0 g/L (in 234 h) was achieved. A significant antimicrobial activity, surface activity, and emulsion ability were recorded. The native sophorolipid was found as enhancer of detergent efficacy of commercial detergent, tested on complex, smudge and oil contaminated clothes. Molecular weight of the C12 (605/623) and C14 (633/651) sophorolipids were determined by LC-MS which revealed it as diacetylated sophorolipid. This study is being important in terms of yield, which is better than the previously reported.
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Enhanced sophorolipid production by feeding-rate-controlled Fed-Batch Culture
Bioresource Technology, 2009Co-Authors: Young-bum Kim, Hyun Shik Yun, Eun-ki KimAbstract:To develop the easier control method for Fed-Batch Culture of sophorolipid production, we chose rapeseed oil as the most productive oil and compared their productivities in relation to different concentrations of glucose. The optimal concentration of glucose was 30 g/L for sophorolipid production. A Fed-Batch method was conducted using Candida bombicola ATCC 22214 with rapeseed oil as a secondary substrate. The feeding rate of rapeseed oil was dependent on pH and was calculated by the consumption rate of NaOH and rapeseed oil. The glucose concentration was constantly maintained between 30 and 40 g/L. As a result, we have produced a crude sophorolipid up to 365 g/L for 8 days through a feeding-rate-controlled Fed-Batch process.
Sang Yup Lee - One of the best experts on this subject based on the ideXlab platform.
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production of poly 3 hydroxybutyrate by Fed Batch Culture of filamentation suppressed recombinant escherichia coli
Applied and Environmental Microbiology, 1997Co-Authors: Fulai Wang, Sang Yup LeeAbstract:Recombinant Escherichia coli XL1-Blue harboring a high-copy-number plasmid containing the Alcaligenes eutrophus polyhydroxyalkanoate synthesis genes could efficiently synthesize poly(3-hydroxybutyrate) (PHB) in a complex medium containing yeast extract and tryptone but not in a defined medium. One of the reasons for the reduced PHB production in a defined medium was thought to be severe filamentation of cells in this medium. By overexpressing an essential cell division protein, FtsZ, in recombinant E. coli producing PHB, filamentation could be suppressed and PHB could be efficiently produced in a defined medium. A high PHB concentration of 149 g/liter, with high productivity of 3.4 g of PHB/liter/h, could be obtained by the pH-stat Fed-Batch Culture of the filamentation-suppressed recombinant E. coli in a defined medium. It was also found that insufficient oxygen supply at a dissolved oxygen concentration (DOC) of 1 to 3% of air saturation during active PHB synthesis phase did not negatively affect PHB production. By growing cells to the concentration of 110 g/liter and then controlling the DOC in the range of 1 to 3% of air saturation, a PHB concentration of 157 g/liter and PHB productivity of 3.2 g of PHB/liter/h were obtained. For the scale-up studies, Fed-Batch Culture was carried out in a 50-liter stirred tank fermentor, in which the DOC decreased to zero when cell concentration reached 50 g/liter. However, a relatively high PHB concentration of 101 g/liter and PHB productivity of 2.8 g of PHB/liter/h could still be obtained, which demonstrated the possibility of industrial production of PHB in a defined medium by employing the filamentation-suppressed recombinant E. coli.
Rosa Olivia Canizaresvillanueva - One of the best experts on this subject based on the ideXlab platform.
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Batch and Fed Batch Culture of scenedesmus incrassatulus effect over biomass carotenoid profile and concentration photosynthetic efficiency and non photochemical quenching
Algal Research-Biomass Biofuels and Bioproducts, 2016Co-Authors: Juan Cristobal Garciacanedo, Eliseo Cristianiurbina, Cesar M Floresortiz, Teresa Poncenoyola, Fernando Esparzagarcia, Rosa Olivia CanizaresvillanuevaAbstract:Abstract The microalga Scenedesmus incrassatulus was cultivated in Batch and Fed-Batch Culture modes under three different nitrogen concentrations (N). Considering that nitrogen limitation results in carotenoid accumulation, main objectives of this work were to assess carotenoid concentration and the following fluorescence parameters: maximum photosynthetic efficiency (Fv/Fm), operational photosynthetic efficiency (Fq′/Fm′) and the non-photochemical quenching (NPQ) at different N concentrations in the Culture media, using Batch and Fed-Batch Culture modes. In all treatments, carotenoid concentration reached maximal level when N concentration in the medium was almost completely depleted. Carotenoid concentrations in Fed-Batch treatments were up to 3 times higher than Batch Culture treatments. Maximum dry weight of 4.05 ± 0.04 g L − 1 and cell concentration of 8.24 × 10 7 cell mL − 1 was obtained using the higher N concentration in Fed-Batch, these values were approximately 3 times higher than the obtained in Batch Culture. Fv/Fm showed the highest magnitude when the initial N concentration in the Culture medium was higher, for both Culture modes. Results showed that the Fed-Batch Culture of S. incrassatulus promotes a higher Fv/Fm than Batch Culture (up to 0.78). The application of Fed-Batch Culture had the effect of stabilizing the values of Fv/Fm during feeding period. In all Fed-Batch treatments the maximum Fq′/Fm′ was detected during the feeding period, which had maximum values ranging from 0.47–0.58. In Fed-Batch Culture mode NPQ showed no direct relationship with total carotenoid concentration. ETR was higher in Fed Batch than in Batch cultivation. In Batch cultivation mode ETR had values ranging from 2 to 56 μmol electrons m − 2 s − 1 . ETR increased 6 fold in Fed-Batch cultivation when irradiance was increased, having values up to 610 μmol electrons m − 2 s − 1 . A good cultivation strategy for biocompound production could be the use of Fed Batch cultivation aimed to return nutrients like nitrogen to its initial condition.
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Batch and Fed Batch Culture of scenedesmus incrassatulus effect over biomass carotenoid profile and concentration photosynthetic efficiency and non photochemical quenching
Algal Research-Biomass Biofuels and Bioproducts, 2016Co-Authors: Juan Cristobal Garciacanedo, Eliseo Cristianiurbina, Cesar M Floresortiz, Teresa Poncenoyola, Fernando Esparzagarcia, Rosa Olivia CanizaresvillanuevaAbstract:Abstract The microalga Scenedesmus incrassatulus was cultivated in Batch and Fed-Batch Culture modes under three different nitrogen concentrations (N). Considering that nitrogen limitation results in carotenoid accumulation, main objectives of this work were to assess carotenoid concentration and the following fluorescence parameters: maximum photosynthetic efficiency (Fv/Fm), operational photosynthetic efficiency (Fq′/Fm′) and the non-photochemical quenching (NPQ) at different N concentrations in the Culture media, using Batch and Fed-Batch Culture modes. In all treatments, carotenoid concentration reached maximal level when N concentration in the medium was almost completely depleted. Carotenoid concentrations in Fed-Batch treatments were up to 3 times higher than Batch Culture treatments. Maximum dry weight of 4.05 ± 0.04 g L − 1 and cell concentration of 8.24 × 10 7 cell mL − 1 was obtained using the higher N concentration in Fed-Batch, these values were approximately 3 times higher than the obtained in Batch Culture. Fv/Fm showed the highest magnitude when the initial N concentration in the Culture medium was higher, for both Culture modes. Results showed that the Fed-Batch Culture of S. incrassatulus promotes a higher Fv/Fm than Batch Culture (up to 0.78). The application of Fed-Batch Culture had the effect of stabilizing the values of Fv/Fm during feeding period. In all Fed-Batch treatments the maximum Fq′/Fm′ was detected during the feeding period, which had maximum values ranging from 0.47–0.58. In Fed-Batch Culture mode NPQ showed no direct relationship with total carotenoid concentration. ETR was higher in Fed Batch than in Batch cultivation. In Batch cultivation mode ETR had values ranging from 2 to 56 μmol electrons m − 2 s − 1 . ETR increased 6 fold in Fed-Batch cultivation when irradiance was increased, having values up to 610 μmol electrons m − 2 s − 1 . A good cultivation strategy for biocompound production could be the use of Fed Batch cultivation aimed to return nutrients like nitrogen to its initial condition.