Purification of lysozyme by microporous PVDF membrane-based chromatographic process

The Utilization of Chicken Egg White Waste-Modified Nanofiber Membrane for Anionic Dye Removal in Batch and Flow Systems: Comprehensive Investigations into Equilibrium, Kinetics, and Breakthrough Curve

This study investigated the use of chicken egg white (CEW) waste immobilized on weak acidic nanofiber membranes for removing the anionic acid orange 7 (AO7) dye in batch and continuous flow modes. Different experiments were conducted to evaluate the effectiveness of CEW-modified nanofiber membranes for AO7 removal, focusing on CEW immobilization conditions, adsorption kinetics, and thermodynamics. The CEW-modified nanofiber membrane (namely NM-COOH-CEW) exhibited a maximum AO7 adsorption capacity of 589.11 mg/g within approximately 30 min. The Freundlich isotherm model best represented the equilibrium adsorption data, while the adsorption kinetics followed a pseudo-second-order rate model. Breakthrough curve analysis using the Thomas model and the bed depth service time (BDST) model showed that the BDST model accurately described the curve, with an error percentage under 5%. To investigate AO7 elution efficiency, different concentrations of organic solvents or salts were tested as eluents. The NM-COOH-CEW nanofiber membrane exhibited promising performance as an effective adsorbent for removing AO7 dye from contaminated water.

Planar chromatography and immunodetection of hydrocarbons on polyvinylidene difluoride membranes

Fast, cheap, and simple separation of lipids and hydrocarbons can currently be achieved using thin-layer chromatography. Here, we describe an alternative planar chromatographic method using polyvinylidene difluoride membranes as the stationary phase. The procedure has the same advantages of thin-layer chromatography over other expensive and time-consuming techniques, such as high-performance liquid chromatography or gas chromatography. Polyvinylidene difluoride membranes, however, also provide an immediate support for analyte development via immunodetection, are easy to manipulate, and potentially increase the performance of other detection methods. We show that polyvinylidene difluoride membranes are compatible with a variety of solvents that can migrate by capillarity and redistribute analytes between the membrane and the solvent according to their relative affinities, providing a chromatographic separation. We directly test the developed membranes by immunoblotting using anti-squalene antibodies that cross-react with acyclic isoprenoids. Separations of crude oils and plant extracts under different solvent conditions show the potential to resolve hydrocarbon group types and also to provide characteristic fingerprints of plant pigments and squalene degradation products. Polyvinylidene difluoride membranes prove useful as a stationary phase for planar chromatography and for the subsequent immunodetection of the separated compounds, providing a new and simple chromatographic technique to analyze lipids and hydrocarbons.

Adsorption and purification performance of lysozyme from chicken egg white using ion exchange nanofiber membrane modified by ethylene diamine and bromoacetic acid

A high-performance polyacid ion exchange (IEX) nanofiber membrane was used in membrane chromatography for the recovery of lysozyme from chicken egg white (CEW). The polyacid IEX nanofiber membrane (P-BrA) was prepared by the functionalization of polyacrylonitrile (PAN) nanofiber membrane with ethylene diamine (EDA) and bromoacetic acid (BrA). The adsorption performance of P-BrA was evaluated under various operating conditions using Pall filter holder. The results showed that optimal conditions of IEX membrane chromatography for lysozyme adsorption were 10% (w/v) of CEW, pH 9 and 0.1 mL/min. The purification factor and yield of lysozyme were 402 and 91%, respectively. The adsorption process was further scaled up to a larger loading volume, and the purification performance was found to be consistent. Furthermore, the regeneration of IEX nanofiber membrane was achieved under mild conditions. The adsorption process was repeated for five times and the adsorption capacity of adsorber was found to be unaffected.

Removal of dye waste by weak cation-exchange nanofiber membrane immobilized with waste egg white proteins

In this research, a protein nanofiber membrane (P-COOH-CEW) was developed to treat the dye waste. Initially, polyacrylonitrile nanofiber membrane (PAN) was prepared by electrospinning, followed by heat treatment, alkaline treatment, and neutralization to obtain weak cation exchange nanofiber membrane (P-COOH). The P-COOH membrane was chemically coated with chicken egg white (CEW) proteins to obtain a 3D structure of complex protein nanofiber membrane (P-COOH-CEW). The composite prepared was characterized with Fourier Transform Infrared analysis (FTIR), Scanning Electron Microscopy (SEM), and thermogravimetric analysis (TGA). Further, the composite was evaluated by investigating the removal of Toluidine Blue O (TBO) from aqueous solutions in batch conditions. Different operating parameters - coupling of CEW, shaking rate, initial pH, contact time, temperature, and dye concentration were studied. From the results, maximum removal capacity and equilibrium association constant was determined to be 546.24 mg/g and 10.18 mg/mg, respectively at pH 10 and 298 K. The experimental data were well fitted to pseudo-second order model. Furthermore, desorption studies revealed that the adsorbed TBO can be completely eluted by using 50% ethanol or 50% glycerol in 1 M NaCl solution. Additionally, the reuse of P-COOH-CEW membrane reported to have 97.32% of removal efficiency after five consecutive adsorption/desorption cycles.

Effect of magnetic field on the ultrafiltration of bovine serum albumin

This work evaluates the effects of a static magnetic field on the permeation of bovine serum albumin (BSA) in a tangential ultrafiltration membrane module. Experimental tests were carried out at different pHs using a poly(sulfone) membrane with molecular weight cut off of 60 kDa under the influence of a 0.4 T neodymium-iron-boron magnetic field. Results showed an increase in the permeate flux of water after the cleaning procedures of the new and reused membranes in the presence of the magnetic field. The elusive mechanism of magnetic memory is also shown to take place for the water fluxes fully recovered after the cleaning procedures when the magnetic field was applied to the system before the permeation. When the magnetic field was applied during permeation, the water fluxes presented lower percent of recuperation after the cleaning procedures, thus suggesting that the BSA solution may have somewhat been influenced by magnetic memory.

Preparation of dye–ligand affinity chromatographic packings based on monodisperse poly(glycidylmethacrylate-co-ethylenedimethacrylate) beads and their chromatographic properties

Monodisperse porous particles, poly(glycidylmethacrylate-co-ethylenedimethacrylate), P(GMA-EDMA) beads with diameter of 7 microm were prepared by a single-step swelling and polymerization method. The polymer particles were advantaged through immobilization of Procion Bule MX-R, which was incubated by epichlorohydrin via the epoxide groups on the particles surface. The Procion Bule MX-R-immobilized P(GMA-EDMA) beads were mechanically stable and acted as the rigid matrix for column chromatography in HPLC mode. The chromatographic properties of the dye-ligand affinity chromatographic stationary phase for biopolymers separation are discussed. This affinity column has advantages of enabling biopolymer separation, high efficiency and low backpressure. Lysozyme and BSA were fast separated within 10min using this affinity column. The column was also used for the purification of lysozyme from chicken egg white.

Selection of Ligands for Affinity Chromatography Using Quartz Crystal Biosensor

This paper described a new strategy for rapid selecting ligands for application in affinity chromatography using a quartz crystal microbalance (QCM) biosensor. An aminoglycoside antibiotic drug, kanamycin (KM), was immobilized on the gold electrodes of the QCM sensor chip. The binding interactions of the immobilized KM with various proteins in solution were monitored as the variations of the resonant frequency of the modified sensor. Such a rapid screen analysis of interactions indicated clearly that KM-immobilized sensor showed strong specific interaction only with lysozyme (LZM). The resultant sensorgrams were rapidly analyzed by using a kinetic analysis software based on a genetic algorithm to derive both the kinetic rate constants (k(ass) and k(diss)) and equilibrium dissociation constants (K(D)) for LZM-KM interactions. The immobilized KM showed higher affinity to LZM with a dissociation constant on the order of 10(-5) M, which is within the range of 10(-4)-10(-8) M and suitable for an affinity ligand. Therefore, KM was demonstrated for the first time as a novel affinity ligand for purification of LZM and immobilized onto the epoxy-activated silica in the presence of a high potassium phosphate concentration. The KM immobilized affinity column has proved useful for a very convenient purification of LZM from chicken egg white. The purity of LZM obtained was higher than 90%, as determined by densitometric scanning of sodium dodecyl sulfate-polyacrylamide gel electrophoresis of purified fraction. These results confirmed that the selected KM ligand is indeed a valuable affinity ligand for purification of LZM. The new screening strategy based on a QCM biosensor is expected to be a promising way for rapid selecting specific ligands for purifying other valuable proteins.

Effects of protein–protein interaction in ultrafiltration based fractionation processes

This paper discusses the use of pulsed sample injection ultrafiltration (UF) for investigating protein-protein interaction, particularly its effect on protein transmission through UF membranes. Several binary protein mixtures were investigated; the proteins in each mixture being selected such that one of the proteins in the pair would be preferentially transmitted while the other would be either totally or substantially retained. The "retained" protein either decreased or increased or did not affect the sieving coefficient of the "transmitted" protein, this depending the type of protein-protein interaction, that is, associative, repulsive, or neutral. The type of protein-protein interaction depended on the particular protein pair under investigation as well as on the operating conditions used (pH and salt concentration). The magnitude of either decrease or increase in transmission of a preferentially transmitted protein due to the presence of a retained protein was found to be independent of the manner in which the proteins were injected into the system, that is, simultaneous or sequential. These magnitudes however correlated well with the ratio of the two proteins present in the feed.

Affinity membrane chromatography: relationship of dye-ligand type to surface polarity and their effect on lysozyme separation and purification

Two different dye-ligands, i.e. Procion Brown MX-5BR (RB-10) and Procion Green H-4G (RG-5) were immobilised onto poly(2-hydroxyethylmethacrylate) (pHEMA) membranes. The polarities of the affinity membranes were determined by contact angle measurements. Separation and purification of lysozyme from solution and egg white were investigated. The adsorption data was analysed using two adsorption kinetic models the first order and the second order to determine the best-fit equation for the separation of lysozyme using affinity membranes. The second-order equation for the adsorption of lysozyme on the RB-10 and RG-5 immobilised membranes systems is the most appropriate equation to predict the adsorption capacity for the affinity membranes. The reversible lysozyme adsorption on the RB-10 and RG-5 did not follow the Langmuir model, but obeyed the Temkin and Freundlich isotherm model. Separation and purification were monitored by determining the lysozyme activity using Micrococcus lysodeikticus as substrate. The purities of the eluted lysozyme, as determined by HPLC, were 76 and 92% with recovery 63 and 77% for RB-10 and RG-5 membranes, respectively. For the separation and purification of lysozyme the RG-5 immobilised membrane provided the best results. The affinity membranes are stable when subjected to sanitization with sodium hydroxide after repeated adsorption-elution cycles.