Polymer and alcohol‐based three‐phase partitioning systems for separation of polysaccharide and protein

Abstract

BackgroundNatural polymers are macromolecules produced by living organisms, with a wide range of applications and relevance for the development of a circular economy. However, large‐scale production is still hindered by several factors, such as downstream processing. In this work, three‐phase partitioning (TPP) systems were investigated for separation of model polysaccharide (dextran, alginate and gum arabic) from protein (Bovine serum albumin (BSA) and lysozyme). The recyclability of phase‐forming compounds used to form the extractive platform was assessed by ultrafiltration (UF). This study contributes to development of production processes for biopolymers from fermented waste by proposing an effective separation technique for fractionation of biopolymers. Previously such biopolymers were only collected as mixtures, and with the studied approaches, also fractionation may be applied of polysaccharides from proteins. With the chosen systems, the scope of TPP systems is expanded by using another class of phase‐forming compound (polymers), and in addition, UF was studied as a versatile regeneration approach.ResultsWithin the TPP approach, the best separation of dextran from BSA was achieved using TPP systems composed of 25 wt% PEG + 25 wt% K3C6H5O7 and 36 wt% EtOH + 10 wt% K3PO4, in which more than 95% of dextran and BSA were found as precipitate and partitioned to top phase (PEG or EtOH‐rich), respectively. By using other model compounds, it was found that the molecular weight and charge of biopolymer play a key role in the yield and selectivity of TPP systems. Finally, by using ultrafiltration/diafiltration, about 99% of ethanol and phosphate salt used to form the extractive platform could be retrieved in the permeate stream.ConclusionThe high extraction yields, selectivity and recyclability of phase‐forming compounds confirm the potential of polymer‐based and alcohol‐based TPP systems to fractionate biopolymer mixtures.This article is protected by copyright. All rights reserved.

Fractionation of Extracellular Polymeric Substances by Aqueous Three-Phase Partitioning Systems

“…Compared to our previous investigation using the same ILs and phosphate salt for the fractionation of model biopolymers, 41 a comparable trend was observed based on the type of IL. That is, [C 4 mim]Cl was also the most suitable IL for the fractionation of model biopolymers.…”

“…The selection of ATPS with the potential to form a TPP system was done based on the data of ternary phase diagrams available in the literature, − and their use for the fractionation of model mixtures containing only BSA and alginate has been proven. , Minimizing the use of phase-forming compounds was also considered for the selection of the mixture point. The results from our previous study using model components were also considered as leading, as the concentrations at which two phases formed were expected to be similar.…”

“…To the best of our knowledge, the use of the ATPS/TPP approach as a fractionation technique for EPS produced by MMCs has not yet been explored beyond our own studies with model compounds, , i.e., no studies with real EPS-rich broths have been reported. It is anticipated that by fractionating the different classes of biopolymers present in the EPS matrix, full valorization can be achieved, and other applications (potentially with more added-value) may be unlocked beyond the current applications for unfractionated EPS mixtures.…”

Primary recovery strategies of low‐molecular‐weight toxins from Crotalus molossus nigrescens and Crotalus atrox using aqueous two‐phase and three‐phase partition systems

“…9 ATPS are formed when two water-soluble molecules (e.g., two polymers or a polymer and salt) are mixed above a certain critical concentration, when phase separation takes place. 9,10 This separation method has been used extensively for the separation of a wide type of biomolecules such as enzymes, 11 proteins, 12 peptides, 13 biopolymers, 14 antibodies, 15 and low-molecular-weight products, 16 among others molecules. Although several molecules from different sources have been recovered using ATPS, its use for snake venom fractionation has been poorly explored.…”

“…23 Given the difference in compositions of each phase, TPP has been used to recover a wide range of molecules including antibodies, 25 low-molecular-weight compounds, 24 oils, 23,26 enzymes, 22 polysaccharides, and proteins. 10 To the best of our knowledge, there is no report regarding recovery of snake venoms using TPP.…”