(Liquid+liquid) equilibria of polymer-salt aqueous two-phase systems for laccase partitioning: UCON 50-HB-5100 with potassium citrate and (sodium or potassium) formate at 23°C

Abstract

a b s t r a c tAqueous two-phase systems (ATPS) are recognized as very suitable techniques for the recovery of target solutes in biological applications. Three new phase diagrams of (UCON 50-HB-5100 + potassium citrate + water), (UCON 50-HB-5100 + sodium formate + water), and (UCON 50-HB-5100 + potassium formate + water) systems were measured at 23°C. The binodal curves were successfully described using the empirical equation suggested by Merchuk and co-workers. The reliability of the tie-line data experimentally determined was evaluated using the equations reported by Othmer-Tobias and Bancroft and satisfactory linearity was obtained for all ATPS. Among the salts studied, potassium citrate proved to be the most effective in ATPS formation, providing the largest heterogeneous region. Besides, the effect of both anions and cations in the size of the heterogeneous region and in the slope of the tie-lines has been compared. For the same salts and conditions, the heterogeneous region using UCON as the phase-forming polymer is larger than using polyethylene glycol. Furthermore, laccase partition in the UCON-salt ATPS was studied and it was found that in all cases enzyme partition occurred preferably to the bottom phase (salt-rich phase). Laccase concentration in the salt-rich phase was approximately 2-fold that in the top phase, thus UCON-salt ATPS can be a suitable biphasic system for laccase extraction.

Separation of Phenyl Acetic Acid and 6-Aminopenicillanic Acid Applying Aqueous Two-Phase Systems Based on Copolymers and Salts

“…In this work, the effect of the structure of copolymer, temperature and salt anion/cation on the binodal curves were provided smaller two phase region. This behavior was observed in several literatures [26,27,30] . and relative solubility number (RSN) [31].…”

Recovery of Peniophora cinerea laccase using aqueous two-phase systems composed by ethylene oxide/propylene oxide copolymer and potassium phosphate salts

“…The use of ATPS for laccase recovery from culture media has been few explored up till now. Besides the application for pure commercial laccase partition [23,31], only three other studies reporting the use of ATPSs for laccase purification were recently published. All these studies concluded that ATPSs have potential for application in downstream processes in the recovery and primary purification of laccase from fermentation medium.…”

“…2 for UCON-K 2 HPO 4 ATPS. Protein partition coefficient was obtained as the slope of this straight line, as previously described [23,31]. The only exception was UCON-KPB ATPS, where only four replicates were used to obtain the partition coefficient.…”

Thermoseparating aqueous two‐phase systems: Recent trends and mechanisms

“…The partitioning of some bioparticles such as plasmid DNA is very sensitive to slight changes in concentration of phase‐forming polymer. During investigation of laccase extraction, the shortest TLL of four systems which composed of Ucon with citrate and formate salts were chosen as least phase‐forming components are required and have lowest viscosities .…”