Synergistic extraction of α-Lactalbumin and β-Lactoglobulin from acid whey using aqueous biphasic system: Process evaluation and optimization

Recovery of value-added products from wastewater using Aqueous Two-Phase Systems - A review

Aqueous two-phase system (ATPS) is long seen as a technique that promotes higher purity and yield in a single step. It is witnessing increased acceptance as a preferred choice for combined goals of concentration, separation and purification of a target product, be it industrially valuable or environmentally contaminating. Purification of biomolecules like enzymes, proteins, nucleic acids, viruses, etc. has been the forte of ATPS. Currently, the technique is used for concentrating the toxic fractions from diverse industrial let offs, from food, dairy, beverage, pharmaceuticals, agriculture, dyeing, tannery and metal-processing industries. Apart from being simple, efficient, rapid, flexible, economical, and biocompatible, the selectivity, purity and yield are on par and sometimes higher than the traditional downstream steps. From an industrial angle too, problems related to scale-up of ATPS are being actively addressed. Many novel approaches are being added by way of varying ATPS components to increase the yield and purity. Another case in point is the inclusion of optimization techniques for zeroing in on the precise setting of the operating parameters. With increasing impetus to the approach, we attempt to draw attention from academia and industries, alike, that are developing novel tweaks to the currently existing practices in ATPS. This review aims to assess and evaluate the different types of ATPS that have been used for the recovery of valuables and contaminants from industrial waste discharges.

Aqueous two phase partitioning of Pisum sativum lectin in PEG/citrate salt system

Pisum sativum lectin (Psl) is a metalloprotein which is in the center of research interest because of its HIV-1 reverse transcriptase inhibitory activity and mitogenic activity. The application of this lectin in various fields demands the economically feasible and scalable purification strategy other than affinity chromatography. The suitability of aqueous two phase system (ATPS) composed of poly ethylene glycol (PEG) with different salts (sodium citrate, potassium citrate, and ammonium citrate) was evaluated for better partitioning of Psl. The significant factors such as molar mass and concentration of PEG, type and concentration of salts, the effect of tie line length (TLL), ionic strength, and pH were studied to select a suitable system for better partitioning of Psl. ATPS comprising of 18% PEG 6000, 16% sodium citrate, 1% NaCl at the operating condition of pH 8, 40.23% of TLL, and the volume ratio of 1.32 was found to be the best system which gave a maximum partition coefficient and yield of 14.5% and 98.66%, respectively.

Partitioning Behavior of Lysozyme and α-lactalbumin in Aqueous Two-Phase System Formed by Ionic Liquids and Potassium Phosphate

Nowadays ionic liquids (ILs), because of their “green” characteristics, have been used for analytical and separation processes. Therefore the partitioning of lysozyme and α-lactalbumin using aqueous two-phase systems (ATPSs) composed of an ionic liquid (chloride 1-ethyl-3-methylimidazolium) and inorganic salts (K2HPO4, KH2PO4) was studied. Phase equilibrium diagrams were obtained to explore the effect of the different temperatures (293.15, 303.15, 313.15, and 323.15) K and pH (7.5, 8.0, and 8.5) used for the partitioning studies. For both proteins, partition coefficients decreased with increasing temperature. The pH influenced the partition coefficients of lysozyme and α-lactalbumin. The thermodynamic parameters (ΔH◦, ΔS◦, ΔG◦) indicate thermodynamic differences between the partitioning of lysozyme and α-lactalbumin in this system. The ΔH◦, ΔS◦, and ΔG◦values of the process studied showed that this process is spontaneous. This work demonstrates the possible use of ATPSs with ILs and inorganic salts as a methodology for the partitioning of lysozyme and α-lactalbumin.