Extraction of Proteins by Reversed Micellar Solution in a Packed Column
01 Apr 1999-Journal of Chemical Engineering of Japan (The Society of Chemical Engineers, Japan)-Vol. 32, Iss: 2, pp 211-216
TL;DR: In this paper, a packed column was used for protein extraction and the results indicated that the resistance of protein solubilization at the interface controlled protein transfer from the aqueous into the organic phase.
Abstract: Protein extraction using reversed micelles is carried out in a packed column. The extracted fraction of lysozyme and the overall capacity coefficient, Kca, are measured for various flow rates and different packing materials. The same column without packings is also used as a spray column. By using a flat interface stirred cell, mass transfer coefficients for the aqueous and the organic phases are measured as well as the protein transfer rate. The results indicate that the resistance of protein solubilization at the interface controls protein transfer from the aqueous into the organic phase. The extracted fraction in the packed column is about three times larger than that for the spray column due to the larger holdup of dispersed phase in the packed column. Since the drops hardly break or coalesce in the packed bed and the protein transfer coefficient is constant, the overall capacity coefficient is controlled by the holdup of dispersed phase. On the assumption that the drop size and the transfer coefficient are constant, the correlation between holdup and flow rates is obtained. Values of Kca and the extracted fraction are calculated from the holdup correlation. Effects of packing materials on the values of Kca are small. A high protein activity is retained in the packed column operation, which indicates that the packed column does little harm to proteins due to moderate mixing.
Citations
More filters
TL;DR: In this paper, the authors applied the response surface methodology to optimize the separation of dl -tryptophan from aqueous solution, and obtained the maximum Y (100%) was obtained by employing the following predicted optimum extraction conditions: a pH of 12.46, a carrier concentration of 22.22%, and an initial amino acid concentration of 4.97 mM.
114 citations
TL;DR: The paper highlights the importance of how the reversed micelle microenvironment should be arranged with respect to the preservation of the activity of the enzyme as target product or biocatalyst as well as the trials of performing continuous processes involving reversed micellar separation and reaction media.
112 citations
TL;DR: The diffusion model could describe quite well the extraction of lysozyme from hen egg white using reversed micelles and the optimal conditions for the extraction at steady state were found to be a rotor speed of 5 rpm, an aqueous-to-organic phase flow ratio of 60:20 mL/min, and a total throughput of 80mL/min.
Abstract: The gentle mixing characteristics of a Graesser contactor can help to avoid the formation of stable emulsions, which is one advantage of this type of contactor when used with reversed micellar extraction. In this study, the performance of the Graesser contactor in lysozyme extraction from hen egg white is investigated. The concentration profile of lysozyme in the aqueous and organic phases indicated that, while substantial axial mixing occurred in the contactor, the extraction yield was in the range of 97% to 99%. The number of mass transfer units (N(ox)) was determined using a diffusion model, and the influence of aqueous-to-organic phase flow ratio, rotor speed, and total throughput on contactor performance was studied. It was found that the diffusion model could describe quite well the extraction of lysozyme from hen egg white using reversed micelles. The optimal conditions for the extraction at steady state were found to be a rotor speed of 5 rpm, an aqueous-to-organic phase flow ratio of 60:20 mL/min, and a total throughput of 80 mL/min. In addition, back-extraction was also performed using the conventional method (1.5 M KBr at pH 11.5) in the contactor. It was found that this mass transfer was not well described by a diffusion model, although 85% of the lysozyme could be recovered with the operating conditions used: a rotor speed of 10 rpm, and an aqueous-to-organic flow rate of 10:10 mL/min.
32 citations
26 Feb 2003
TL;DR: Food science and food biotechnology, Food science andFood biotechnology , کتابخانه دیجیتال جندی شاپور اهواز
Abstract: This groundbreaking book provides a balanced and organized discussion of the interactions of food science and biotechnology at the molecular and industrial levels. Carefully selected and reviewed contributions stress the aspects of modern bioprocessing, analysis, and quality control that are common to both food science and biotechnology. The detailed analysis of specific examples of upstream and downstream processes assists readers in understanding the underlying principles and the similarities between applications. Throughout the book there is a strong emphasis on emerging technologies, combined methods for preserving food and biological materials, and descriptions of state-of-the-art equipment and techniques.
21 citations
TL;DR: Both sides of the interfaces of the system KCl–KCl have an adequate flexibility that extraction and back-extraction of lysozyme through the membrane are attainable, although the transfer rate is rather low.
20 citations
References
More filters
TL;DR: In this paper, the relation of P to conveniently available properties of dilute solutions is generalized to permit estimation of diffusion coefficients for engineering purposes for convective transport due to volume changes on mixing is negligible and other possible modes of mass transfer are not operative.
Abstract: Equation i 1) is strictly applicable in ideal dilute solutions in which convective transport due to volume changes on mixing is negligible, and in which other possible modes of mass transfer are not operative. This paper represents an attempito generalize the relation of P to conveniently available properties of dilute solutions so as to permit estimation of diffusion coefficients for engineering purposes.
4,166 citations
TL;DR: A simple activity measurement of Lysozyme is described in this article, where the authors present a simple activity measurement of the enzyme and show that it is a simple molecule to measure.
Abstract: (1971). A Simple Activity Measurement of Lysozyme. Agricultural and Biological Chemistry: Vol. 35, No. 7, pp. 1154-1156.
690 citations
364 citations
TL;DR: In this paper, differentially protein extractions were measured with two types of extractants: inverted micelles and two-phase aqueous systems, and the results showed that hollow-fiber extractions are substantially faster than those possible in conventional equipment.
Abstract: Differential protein extractions were measured with two types of extractants: inverted micelles and two-phase aqueous systems. The results show that hollow-fiber extractions are substantially faster than those possible in conventional equipment. The extractions are not compromised by loading or flooding because the flows of extractant and raffinate are almost completely independent. Mass transfer coefficients inferred from the measurements both support and extend design equations for these contactors.
217 citations
TL;DR: It was observed that the extent of protein solubilization could be controlled by varying the ionic strength of the aqueous phase equilibrated with the micellar phase.
Abstract: The controlled solubilization of proteins in a reverse micelle-containing organic phase is considered as a method for separation of proteins by liquid-liquid extraction. Cytochrome-C was transferred between a bulk aqueous phase and a micellar phase, using the Aerosol OT-isooctane system of surfactant and solvent. It was observed that the extent of protein solubilization could be controlled by varying the ionic strength of the aqueous phase equilibrated with the micellar phase.The protein transferred into the micellar phase rapidly, under conditions of low ionic strength, and transferred out of the micelles relatively slowly, under conditions of high ionic strength. It is proposed that the effect of the ionic strength was to alter the electrostatic interaction between the surface charge of the protein and the charged interior of the reverse micelle by Debye screening.
185 citations