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Chau-jen Lee - One of the best experts on this subject based on the ideXlab platform.
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ExtraCtion of Cephalosporin C from whole broth and separation of desaCetyl Cephalosporin C by aqueous two‐phase partition
Biotechnology and bioengineering, 1994Co-Authors: Wu‐yung Yang, Chun‐der Lin, I-ming Chu, Chau-jen LeeAbstract:Cephalosporin C was extraCted from diluted or whole broth by PEG/salt aqueous two-phase systems. Parameters suCh as PEG moleCular weight, salt type, pH, and salt ConCentration were investigated for finding a suitable extraCtion system. In PEG 600/ammonium sulfate or phosphate systems, K(C) (partition CoeffiCienCt of Cephalosporin C) was observed to be larger than 1, with K(d) (partition CoeffiCient of desaCetyl Cephalosporin C) being smaller than 1. The partiCular values of these CoeffiCients would imply that the diffiCult separation of Cephalosporin C and desaCetyl Cephalosporin C Could possibly be aChieved via the aqueous two-phase extraCtion. The addition of surfaCtants, water-misCible solvents, and neutral salts for enhanCement of the separation effiCienCy was also investigated. The addition of surfaCtants to the system did not affeCt the separation effiCienCy substantially. K(C) would inCrease whereas K(d) deCreased as a result of the addition of aCetone, MeOH, EtOH, IPA, and n-BuOH. Meanwhile both K(C) and K(d) would deCrease whenever neutral salts, NaCl, KCl, Kl, or KSCN, were added. The partitioning behavior of Cephalosporin C and desaCetyl Cephalosporin C in filtered, whole, and different batChes of broth was notably quite similar to that of diluted broth. The reCovery yield of Cephalosporin C in whole broth extraCtion was observed to be a funCtion of Centrifugal forCe used in phase separation. (C) 1994 John Wiley & Sons, InC.
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extraCtion of Cephalosporin C from whole broth and separation of desaCetyl Cephalosporin C by aqueous two phase partition
Biotechnology and Bioengineering, 1994Co-Authors: Wuyung Yang, I-ming Chu, Chunder Lin, Chau-jen LeeAbstract:Cephalosporin C was extraCted from diluted or whole broth by PEG/salt aqueous two-phase systems. Parameters suCh as PEG moleCular weight, salt type, pH, and salt ConCentration were investigated for finding a suitable extraCtion system. In PEG 600/ammonium sulfate or phosphate systems, K(C) (partition CoeffiCienCt of Cephalosporin C) was observed to be larger than 1, with K(d) (partition CoeffiCient of desaCetyl Cephalosporin C) being smaller than 1. The partiCular values of these CoeffiCients would imply that the diffiCult separation of Cephalosporin C and desaCetyl Cephalosporin C Could possibly be aChieved via the aqueous two-phase extraCtion. The addition of surfaCtants, water-misCible solvents, and neutral salts for enhanCement of the separation effiCienCy was also investigated. The addition of surfaCtants to the system did not affeCt the separation effiCienCy substantially. K(C) would inCrease whereas K(d) deCreased as a result of the addition of aCetone, MeOH, EtOH, IPA, and n-BuOH. Meanwhile both K(C) and K(d) would deCrease whenever neutral salts, NaCl, KCl, Kl, or KSCN, were added. The partitioning behavior of Cephalosporin C and desaCetyl Cephalosporin C in filtered, whole, and different batChes of broth was notably quite similar to that of diluted broth. The reCovery yield of Cephalosporin C in whole broth extraCtion was observed to be a funCtion of Centrifugal forCe used in phase separation. (C) 1994 John Wiley & Sons, InC.
Hee Moon - One of the best experts on this subject based on the ideXlab platform.
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EffeCt of pH on Adsorption of Cephalosporin C by A NonioniC PolymeriC Sorbent
Adsorption, 1999Co-Authors: Jae-wook Lee, Hee MoonAbstract:Adsorption of Cephalosporin C in a Column Charged with a nonioniC polymeriC sorbent, SP850, was studied at various pH values to assess the effeCt of pH on the dynamiC behavior in Column adsorbers. SinCe Cephalosporin C is amphoteriC, the fraCtions of eaCh ioniC form were CalCulated from the pK values at a given solution pH. Single-speCies isotherm parameters for eaCh ioniC form were simultaneously extraCted from all sets of adsorption equilibrium data measured at several pH values. The mutual interaCtion between different ioniC forms on SP850 was desCribed by a Competitive adsorption, namely the ideal adsorbed solution theory (IAST). This treatment made it possible to simulate the dynamiC behavior of Cephalosporin C at low pH values properly by a dynamiC model whiCh was inCorporated with the mutual Competitive adsorption.
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Adsorption and desorption of Cephalosporin C on nonioniC polymeriC sorbents
Separation and Purification Technology, 1997Co-Authors: Jae-wook Lee, Heung Chul Park, Hee MoonAbstract:Adsorption and desorption of Cephalosporin C on nonioniC polymeriC sorbents were studied in order to obtain basiC information on reCovering Cephalosporin C from aqueous solutions. The sorbents were polystyrene-based maCroretiCular resins with different sorptive CapaCity and pore-size distribution. Cephalosporin C adsorbed on these sorbents was then desorbed by aqueous isopropyl alCohol (IPA) solutions. Adsorption equilibrium data of Cephalosporin C and IPA on these sorbents were found to fit the FreundliCh equation and the desorption of Cephalosporin C by IPA was desCribed by a Competitive adsorption model based on the ideal adsorbed solution theory. Furthermore, a simple dynamiC model was formulated to desCribe both adsorption and desorption breakthrough Curves of Cephalosporin C.
Jae-wook Lee - One of the best experts on this subject based on the ideXlab platform.
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EffeCt of pH on Adsorption of Cephalosporin C by A NonioniC PolymeriC Sorbent
Adsorption, 1999Co-Authors: Jae-wook Lee, Hee MoonAbstract:Adsorption of Cephalosporin C in a Column Charged with a nonioniC polymeriC sorbent, SP850, was studied at various pH values to assess the effeCt of pH on the dynamiC behavior in Column adsorbers. SinCe Cephalosporin C is amphoteriC, the fraCtions of eaCh ioniC form were CalCulated from the pK values at a given solution pH. Single-speCies isotherm parameters for eaCh ioniC form were simultaneously extraCted from all sets of adsorption equilibrium data measured at several pH values. The mutual interaCtion between different ioniC forms on SP850 was desCribed by a Competitive adsorption, namely the ideal adsorbed solution theory (IAST). This treatment made it possible to simulate the dynamiC behavior of Cephalosporin C at low pH values properly by a dynamiC model whiCh was inCorporated with the mutual Competitive adsorption.
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Adsorption and desorption of Cephalosporin C on nonioniC polymeriC sorbents
Separation and Purification Technology, 1997Co-Authors: Jae-wook Lee, Heung Chul Park, Hee MoonAbstract:Adsorption and desorption of Cephalosporin C on nonioniC polymeriC sorbents were studied in order to obtain basiC information on reCovering Cephalosporin C from aqueous solutions. The sorbents were polystyrene-based maCroretiCular resins with different sorptive CapaCity and pore-size distribution. Cephalosporin C adsorbed on these sorbents was then desorbed by aqueous isopropyl alCohol (IPA) solutions. Adsorption equilibrium data of Cephalosporin C and IPA on these sorbents were found to fit the FreundliCh equation and the desorption of Cephalosporin C by IPA was desCribed by a Competitive adsorption model based on the ideal adsorbed solution theory. Furthermore, a simple dynamiC model was formulated to desCribe both adsorption and desorption breakthrough Curves of Cephalosporin C.
Carlos O. Hokka - One of the best experts on this subject based on the ideXlab platform.
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Cephalosporin C produCtion by immobilized Cephalosporium aCremonium Cells in a repeated batCh tower bioreaCtor
Biotechnology and bioengineering, 2004Co-Authors: Antonio José Gonçalves Cruz, Tai Pan, Roberto C. Giordano, Maria Lucia Gonsales Da Costa Araujo, Carlos O. HokkaAbstract:The industrial produCtion of antibiotiCs with filamentous fungi is usually Carried out in Conventional aerated and agitated tank fermentors. Highly visCous non-Newtonian broths are produCed and a Compromise must be found between Convenient shear stress and adequate oxygen transfer. In this work, Cephalosporin C produCtion by biopartiCles of immobilized Cells of Cephalosporium aCremonium ATCC 48272 was studied in a repeated batCh tower bioreaCtor as an alternative to the Conventional proCess. Also, gas-liquid oxygen transfer volumetriC CoeffiCients, kLa, were determined at various air flow-rates and alumina Contents in the biopartiCle. The biopartiCles were Composed of CalCium alginate (2.0% w/w), alumina ( < 44 miCra), Cells, and water. A model desCribing the Cell growth, Cephalosporin C produCtion, oxygen, gluCose, and suCrose Consumption was proposed. To desCribe the radial variation of oxygen ConCentration within the pellet, the reaCtion-diffusion model foreCasting a dead Core biopartiCle was adopted. The kLa measurements with gel beads prepared with 0.0, 1.0, 1.5, and 2.0% alumina showed that a higher kLa value is attained with 1.5 and 2.0%. An expression relating this CoeffiCient to partiCle density, liquid density, and air veloCity was obtained and further utilized in the simulation of the proposed model. BatCh, followed by repeated batCh experiments, were aCComplished by draining the spent medium, washing with saline solution, and pouring fresh medium into the bioreaCtor. Results showed that gluCose is Consumed very quiCkly, within 24 h, followed by suCrose Consumption and Cephalosporin C produCtion. Higher produCtivities were attained during the seCond batCh, as Cell ConCentration was already high, resulting in rapid gluCose Consumption and an early derepression of Cephalosporin C synthesizing enzymes. The model inCorporated this improvement prediCting higher Cephalosporin C produCtivity. © 2003 Wiley PeriodiCals, InC.
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Continuous Cephalosporin C purifiCation: dynamiC modelling and parameter validation
Bioprocess and biosystems engineering, 2002Co-Authors: Marlei Barboza, Carlos O. Hokka, Francisco MaugeriAbstract:A mathematiCal kinetiC model for the adsorption and desorption of Cephalosporin C on Amberlite XAD-2 resin is proposed. The model Can represent Langmuir, FreundliCh or linear isotherms at equilibrium. The intrinsiC kinetiC parameters and adsorption isotherms as well as physiCal parameters suCh as the effeCtive diffusivity and the external mass transfer CoeffiCient were obtained at different temperatures and ethanol ConCentrations. An unfavourable Cephalosporin C adsorption oCCurred when ethanol was present in the solution. It has been shown that at 25°C the ethanol, at ConCentrations from 1.5% to 2.5%, deCreases the Cephalosporin C adsorption. However, this behaviour was not observed at 10°C. The kinetiC model fitted the experimental data well under different Conditions. The model was validated in a Continuous proCess of Cephalosporin C purifiCation using the same resin. The model with the validated parameters is able to prediCt the behaviour of the reaCtor system. The Continuous proCess is Composed of two stirred tank reaCtors with adsorber reCyCle. The adsorption oCCurs in the first stage, and elution of the produCt takes plaCe in the seCond stage with ethanol as eluent. The dynamiC behaviour of the proCess was desCribed using the following parameters: hydrauliC residenCe time for the first (θh1) and seCond stage (θh2), solid residenCe time (θs), initial ConCentration of CPC (C0), inlet ethanol ConCentration (CET0) and kinetiCs parameters.
I-ming Chu - One of the best experts on this subject based on the ideXlab platform.
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Separation of Cephalosporin C and desaCetyl Cephalosporin C by high speed Counter-Current Chromatography in aqueous two-phase systems
Biotechnology Techniques, 1995Co-Authors: Po-chun Lin, I-ming ChuAbstract:In the reCovery of Cephalosporin C (CPC) from fermentation broth, the separation of desaCetyl Cephalosporin C (DAC) is a major ConCern. Multistage extraCtion in aqueous two-phase systems, mainly PEG/ammonium sulfate systems, proved to be promising. In preparative sCale operation, high speed Counter-Current Chromatography (HSCCC) with eCCentriC Columns was used with aqueous two-phase systems to obtain baseline resolution of CPC and DAC. Solvents (e.g. 5% aCetone) or neutral salts (e.g. 1.45% KSCN) added into aqueous two-phase systems enhanCed the separation effiCienCy. Operation parameters of HSCCC suCh as rotational speed and mobile phase flow rate Can affeCt the retention of the stationary phase and HETP.
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ExtraCtion of Cephalosporin C from whole broth and separation of desaCetyl Cephalosporin C by aqueous two‐phase partition
Biotechnology and bioengineering, 1994Co-Authors: Wu‐yung Yang, Chun‐der Lin, I-ming Chu, Chau-jen LeeAbstract:Cephalosporin C was extraCted from diluted or whole broth by PEG/salt aqueous two-phase systems. Parameters suCh as PEG moleCular weight, salt type, pH, and salt ConCentration were investigated for finding a suitable extraCtion system. In PEG 600/ammonium sulfate or phosphate systems, K(C) (partition CoeffiCienCt of Cephalosporin C) was observed to be larger than 1, with K(d) (partition CoeffiCient of desaCetyl Cephalosporin C) being smaller than 1. The partiCular values of these CoeffiCients would imply that the diffiCult separation of Cephalosporin C and desaCetyl Cephalosporin C Could possibly be aChieved via the aqueous two-phase extraCtion. The addition of surfaCtants, water-misCible solvents, and neutral salts for enhanCement of the separation effiCienCy was also investigated. The addition of surfaCtants to the system did not affeCt the separation effiCienCy substantially. K(C) would inCrease whereas K(d) deCreased as a result of the addition of aCetone, MeOH, EtOH, IPA, and n-BuOH. Meanwhile both K(C) and K(d) would deCrease whenever neutral salts, NaCl, KCl, Kl, or KSCN, were added. The partitioning behavior of Cephalosporin C and desaCetyl Cephalosporin C in filtered, whole, and different batChes of broth was notably quite similar to that of diluted broth. The reCovery yield of Cephalosporin C in whole broth extraCtion was observed to be a funCtion of Centrifugal forCe used in phase separation. (C) 1994 John Wiley & Sons, InC.
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extraCtion of Cephalosporin C from whole broth and separation of desaCetyl Cephalosporin C by aqueous two phase partition
Biotechnology and Bioengineering, 1994Co-Authors: Wuyung Yang, I-ming Chu, Chunder Lin, Chau-jen LeeAbstract:Cephalosporin C was extraCted from diluted or whole broth by PEG/salt aqueous two-phase systems. Parameters suCh as PEG moleCular weight, salt type, pH, and salt ConCentration were investigated for finding a suitable extraCtion system. In PEG 600/ammonium sulfate or phosphate systems, K(C) (partition CoeffiCienCt of Cephalosporin C) was observed to be larger than 1, with K(d) (partition CoeffiCient of desaCetyl Cephalosporin C) being smaller than 1. The partiCular values of these CoeffiCients would imply that the diffiCult separation of Cephalosporin C and desaCetyl Cephalosporin C Could possibly be aChieved via the aqueous two-phase extraCtion. The addition of surfaCtants, water-misCible solvents, and neutral salts for enhanCement of the separation effiCienCy was also investigated. The addition of surfaCtants to the system did not affeCt the separation effiCienCy substantially. K(C) would inCrease whereas K(d) deCreased as a result of the addition of aCetone, MeOH, EtOH, IPA, and n-BuOH. Meanwhile both K(C) and K(d) would deCrease whenever neutral salts, NaCl, KCl, Kl, or KSCN, were added. The partitioning behavior of Cephalosporin C and desaCetyl Cephalosporin C in filtered, whole, and different batChes of broth was notably quite similar to that of diluted broth. The reCovery yield of Cephalosporin C in whole broth extraCtion was observed to be a funCtion of Centrifugal forCe used in phase separation. (C) 1994 John Wiley & Sons, InC.