Aqueous Micellar Two-phase Systems Research Articles

Cloud point extraction based on non-ionic surfactants: An ecofriendly tool for recovering papain from papaya latex

The potential use of cloud point extraction with aqueous micellar two-phase systems (AMTPS), formed by the non-ionic biodegradable surfactants Triton X-114 (TX-114) and Genapol X-080 (GX-080), to recover papain (PAP) from fresh papaya latex was evaluated. Binodal curves obtained for both surfactants, in absence and presence of PAP, showed cloud points below 40 °C, the PAP presence slightly favoring the phase separation phenomenon. Partitioning experiments showed that PAP migrated toward the micelle-poor phase independently of the surfactant and the working temperature assayed, this behavior being consistent with this enzyme hydrophilic character. PAP recoveries of over 60% in the poor-micelle phase were obtained when partitioned fresh papaya latex in both surfactant-based AMTPS. TX-114 systems (4.00% w/w, 33 °C) allowed recovering 66% of PAP with a purification factor of 4.6. On GX-080 systems (4.00% w/w, 42 °C) a yield of 78% PAP and a purification factor of 3.7 were achieved. This AMTPS also allowed the separation of PAP from reducing sugars present in papaya latex. These results show that TX-114 and GX-080-based AMTPS could be potentially used as simple and economical tools at recovering PAP from papaya latex.

Recovery of acid proteases from fishery discards with aqueous micellar two-phase systems and their use for X-ray film recycling

The continuous expansion of fish production results in increasing amounts of discards, i.e. viscera, skin and frame, whose inappropriate disposal causes environmental damage. Conversion of this waste into value-added products is one of the best alternatives to reduce the pollution problem. The feasibility of using aqueous micellar two-phase systems (AMTPS), formed by biodegradable Genapol X-080 (GX-080) and sodium citrate, to recover valued acid proteases from surubí (Pseudoplatystoma sp) fishery discards was evaluated for the first time. The effects of biomass load, pH and surfactant concentration on the extraction were analyzed using a two-level full factorial design. GX-080 concentration and biomass load were the most significant factors (p < 0.05). AMTPS formed by GX-080 4% w/w showed a successful performance for the recovering of 69% of AP from the crude extract in the surfactant-rich phase with a purification factor of 1.83. Regard to the storage stability, this extract conserved at least 89% of its proteolytic activity for 76 days at 0 °C. It also showed a notable hydrolyzing activity of the gelatin-silver coating of used X-ray films, thus opening new perspectives on the use of acid proteases for recycling purposes.

Purification of immunoglobulin Y from egg yolk using thermoresponsive aqueous micellar two-phase systems comprising ionic liquids

Immunoglobulin Y (IgY) represents an important class of antibodies, being present in egg yolk, with relevant medical applications and involving non-invasive methods of extraction. However, due to the complexity of egg yolk, the purification levels required for use in most medical applications demands the application of multi-step and cost-intensive techniques. Therefore, it is of upmost importance to develop a biocompatible and cost-effective downstream process to purify IgY from egg yolk. In this work, IgY was purified from the egg yolk water-soluble protein fraction (WSPF) by the application of thermoresponsive aqueous micellar two-phase systems (AMTPS) composed of the non-ionic surfactant Triton X-114 and surface-active ionic liquids (SAILs) as co-surfactants. The best thermoresponsive systems allowed, in a single step, to recover IgY in the surfactant-poor phase with a purity level of 69%, and up to 73% if consecutive extraction cycles are performed, while maintaining the structural integrity of the antibodies. Considering these results, a downstream process was designed and proposed, consisting of four main steps: (i) recovery of the WSPF; (ii) purification of IgY by applying AMTPS; (iii) isolation of the IgY from the main solvents using an ultrafiltration step; (iv) recycling of the AMTPS phase-forming components by precipitating the contaminant proteins.

Effect of dicationic ionic liquids on cloud points of tergitol surfactant and the formation of aqueous micellar two-phase systems

A cloud point evaluation was performed for the nonionic surfactant Tergitol 15-S-7 in aqueous solutions of McIlvaine buffer (pH 7.0). Cloud point temperatures of the selected nonionic surfactant were studied in relation to the effect that the addition of dicationic ionic liquids (ILs) had on the systems. The dicationic ILs with different alkyl spacer lengths were derived from 1, n-bis(3-methylimidazolium-1-yl)alkane bromide ([BisAlk(MIM)2][2Br]) — in which Alk = But, Hex, Oct, and Dec. The dicationic ILs with longer alkyl spacer chains (Alk ≥ 6) led to an increase in the Tergitol’s cloud point values, due to their ability to fold their structures in solution, which increase the interactions of ILs with tergitol in the mixed micelles. This increase was even more pronounced when the concentration of the dicationic ILs was increased. Furthermore, the addition of dicationic ILs increased the micelles size; however, the hydrodynamic diameter of mixed micelles did not depend on the length of the ILs’ alkyl spacer chains. The Tergitol/IL systems with lower critical micellar concentration values will result in higher cloud point values, due to the greater colloidal dispersion stability.

Process design of a continuous biotransformation with in situ product removal by cloud point extraction

AbstractIn this work, a continuous, heterogeneous extractive biocatalysis was realized with penicillin G hydrolysis as a model reaction. Therefore, commercially available structured packing CY from Sulzer were coated with enzyme‐containing gels and their catalytic activity was examined. Thereby, the potential of aqueous micellar two‐phase systems (ATPMS) as an extraction medium was evaluated. Triton X‐114 was used as model surfactant. It was found that the separation efficiency of the packing is not affected by the coating and ATPMS allows for a good separation yield. With these results, different process concepts for the continuous, heterogeneous extractive biocatalysis were compared. Overall, a countercurrent process with side inlet ( = 78.1% ± 1.3%) has shown a great potential for a selective product separation and thus, higher yields in comparison to a monophasic batch operation ( = 51.9% ± 0.6%) as well as a biphasic batch operation ( = 67.6% ± 1.0%, wTriton X‐114 = 5%) were achieved.

Using coarse-grained molecular dynamics to understand the effect of ionic liquids on the aggregation of Pluronic copolymer solutions.

This study is aimed to enhance the understanding of the interaction between ionic liquids (ILs) and non-ionic Pluronic triblock copolymers in aqueous two-phase micellar systems (ATPMS) used for the selective separation/purification of hydrophobic biomolecules. The ILs allow a precise control of the cloud point phase separation temperature (CPT), particularly important when the stability of the molecule is highly dependent on temperature. The effect of choline-based ILs, with two different counter-anions, chloride and hexanoate, was evaluated using molecular dynamics simulations (MD) for F-68 and L-35 Pluronic aqueous solutions. The simulations revealed the role played by the anions during the Pluronic self-assembly, with choline chloride hindering Pluronic aggregation and the choline hexanoate favouring micelle formation and coalescence, in agreement with the experimental data. A detailed study of the accessible surface area of Pluronic showed a progressive dehydration of the Pluronic hydrophilic micelle corona in choline hexanoate mixtures promoting inter-micelle interactions and, consequently, micelle coalescence. With the addition of choline hexanoate, it was observed that the hydrophilic segments, which form the micelle corona, twisted towards the Pluronic micelle core. The electrostatic interaction is also shown to play a key role in this IL-Pluronic aqueous solution, as the hexanoate anions are accommodated in the Pluronic micelle core, while the choline cations are hosted by the Pluronic micelle corona, with the ions interacting with each other during the self-assembly process. In addition, a comparison study of F-68 and L-35 aqueous solutions shows that the IL impact depends on the length of the Pluronic hydrophilic segment. This work provides a realistic microscopic scenario of the complex interactions between Pluronic copolymers and ILs.

Feasibility of packed columns for continuous cloud point extraction with subsequent product recovery

In this work the feasibility of continuous cloud point extraction in packed columns was evaluated. Therefore, extraction of phenylacetic acid with aqueous micellar two-phase systems containing the nonionic surfactant Triton X-114 was chosen as a model system. Raschig rings and structured packing CY from Sulzer were evaluated in terms of HETP, extraction efficiency and enrichment factor. Additionally, the product recovery from the micellar phase was addressed. Back-extraction via pH-shift and adsorption were evaluated to remove phenylacetic acid from the micellar phase, whereas the successful continuous back-extraction in a Kühni column was demonstrated. Finally, several process concepts to recycle the micellar phase and to further purify phenylacetic acid after back-extraction are suggested.

Development of a Microfluidic Platform for R-Phycoerythrin Purification Using an Aqueous Micellar Two-Phase System.

Temperature-dependent aqueous micellar two-phase systems (AMTPSs) have recently been gaining attention in the isolation of high-added-value biomolecules from their natural sources. Despite their sustainability, aqueous two-phase systems, and particularly AMTPSs, have not been extensively applied in the industry, which might be changed by applying process integration and continuous manufacturing. Here, we report for the first time on an integrated microfluidic platform for fast and low-material-consuming development of continuous protein purification using an AMTPS. A system comprised of a microchannel incubated at high temperature, enabling instantaneous triggering of a two-phase system formation, and a microsettler, allowing complete phase separation at the outlets, is reported here. The separation of phycobiliproteins and particularly the purification of R-phycoerythrin from the contaminant proteins present in the aqueous crude extract obtained from fresh cells of Gracilaria gracilis were thereby achieved. The results from the developed microfluidic system revealed that the fractionation performance was maintained while reducing the processing time more than 20-fold when compared with the conventional lab-scale batch process. Furthermore, the integration of a miniaturized ultrafiltration module resulted in the complete removal of the surfactant from the bottom phase containing R-phycoerythrin, as well as in nearly twofold target protein concentration. The process setup successfully exploits the benefits of process intensification along with the integration of various downstream processes. Further transfer to a meso-scale integrated system would make such a system appropriate for the separation and purification of biomolecules with high commercial interest.

Amphiphilic copolymer aqueous solutions with cholinium ionic liquids as adjuvants: New insights into determination of binodal curves and phase-separation mechanisms

Aqueous two-phase micellar systems (ATPMS) are more than simple amphiphilic copolymer or surfactant aqueous solutions since due to the formation of biphasic regimes, at certain temperatures, these can be successfully used for the separation, encapsulation, and formulation of several bio-based compounds. The recent use of ionic liquids (ILs) as adjuvants in the formation of ATPMS have enlarged its “working window”, but the measurement of respective binodal curves is still very empiric and dependent of operator accuracy through the visual determination of cloud-point temperature. In this work, the range of ATPMS using ILs as adjuvants was extended, providing more insights about their phase formation mechanisms, as well as into determination of cloud-point values of the lower critical solution temperature (LCST)-type demixing transition by using the new temperature modulated optical refractometry approach. The binodal curves of ATPMS composed of Pluronic® L35/PBS buffer at pH 7.4 + cholinium ILs were determined, by using two different methods, i.e.: cloud-point temperature (TCP) visual determination versus temperature modulated optical refractometry (TMOR). TMOR method was more sensitive to the determination of biphasic transition, particularly, in highly diluted solutions (< 3.0 wt% of Pluronic L35). The results also established that the addition of cholinium ILs decreased significantly the phase separation temperatures of Pluronic L35/PBS, with an increase of biphasic region (viz. lower of TCP values) as a function of the relative hydrophobicity of the IL anion, i.e.: [Hex]− > [But]− > [Pro]− > [Ac]− > Cl−. The use of cholinium ILs as adjuvants is particularly important to provide mild conditions for ATPMS-based separation and encapsulation strategies, while TMOR-based methods allow an improvement of phase separation determination accuracy.

Separation and purification of curcumin using novel aqueous two-phase micellar systems composed of amphiphilic copolymer and cholinium ionic liquids

Novel aqueous two-phase micellar systems (ATPMS) composed of Pluronic F68, a triblock amphiphilic copolymer, and cholinium-based ionic liquids (ILs) were formulated and applied for separation/purification of curcumin (CCM). CCM stability in the presence of ATPMS components was also evaluated. CCM is stable up to 24 h in copolymer (1.0 – 10.0 wt%) and ILs (0.1 – 3.0 M) aqueous solutions. Very mild phase separation conditions (close to room temperature) were achieved by adding cholinium ILs to the Pluronic F68 + McIlvaine buffer at pH 6.0 solution. The decrease of cloud-point temperature is dependent on the relative hydrophobicity of IL anion, [Hex]− > [But]− > [Pro]− > [Ac]− > Cl−. ATPMS composed of more hydrophobic ILs ([Ch][Hex] > [Ch][But] > [Ch][Pro]) are most efficient in the partition of commercial CCM into polymeric micelles (PMs)-rich phase. The best ATPMS (0.70 M [Ch][But] and 0.60 M [Ch][Hex]-based ATPMS) were then used to purify CCM from a crude extract of Curcuma longa L. Both systems were very selective to separate CCM from protein-based contaminants (selectivity values ≥ 25; purification yields ≥ 12-fold). Pluronic F68-based ATPMS are promising for selective separation of hydrophobic biomolecules by using cholinium-based ILs as adjuvants to adjust phase separation temperatures and biomolecules’ partition.

Optimization of aqueous two-phase micellar system for partial purification of L-asparaginase from Penicillium sp. grown in wheat bran as agro-industrial residue.

L-asparaginase has been used in the remission of malignant neoplasms such as acute lymphoblastic leukemia. The search for new sources of this enzyme has become attractive for therapeutics. Traditional methods for biomolecule purification involve several steps. A two-phase system may be a good strategy to anticipate one of these stages. This study aimed to produce and purify a fungal L-asparaginase through an aqueous two-phase micellar system (ATPMS) using Triton X-114. The fungus Penicillium sp.-encoded 2DSST1 was isolated from Cerrado soil. Plackett-Burman design followed by a 24 full factorial design was used to determine the best conditions to produce L-asparaginase. The evaluated variables were L-asparagine, L-proline, wheat bran, potato dextrose broth, ammonium sulfate, yeast extract, sucrose and glucose concentrations, incubation temperature, incubation period, and initial pH of the culture medium. L-asparaginase quantification was valued by the formation of β-aspartyl hydroxamate. The significant positive variables, L-asparagine, L-proline, potato dextrose broth, and sucrose concentrations, were evaluated at 2 levels (+ 1 and - 1) with triplicate of the central point. After 34 runs, maximum activity (2.33IU/mL) was achieved at the factorial design central point. A central composite design was performed in ATPMS at two levels (+ 1 and - 1) varying Triton X-114 concentration (w/v), separation phase temperature, and crude extract concentration (w/v). The L-asparaginase partition coefficient (K) was considered the experimental design response. Out of the 16 systems that were examined, the most promising presented a purification factor of 1.4 and a yield of 100%.

Recovery and purification of cellulolytic enzymes from Aspergillus fumigatus CCT 7873 using an aqueous two-phase micellar system

PurposeIn this study, an aqueous two-phase micellar system (ATPMS), formed by the non-ionic surfactant Triton X-114, was used to investigate the partitioning of cellulolytic enzymes produced by the filamentous fungus Aspergillus fumigatus CCT 7873.MethodsPerformance of the ATPMS on the partitioning of CMCase (activity on carboxymethyl cellulose) and FPase (activity on filter paper) was investigated by varying the temperature (35, 40, 45, 50, 55, 60, and 65 °C), enzyme crude extract concentration (20, 40, 60, and 80% w/w), and Triton X-114 concentration (2, 4, 6, and 8% w/w) and by adding different inorganic salts (NaCl, CaCl2, MgSO4, and MnSO4) in the system.ResultsAn ATPMS formed with 8% (w/w) Triton X-114 and 40% (w/w) enzymatic crude extract at a system temperature of 55 °C was most favorable for partitioning the tested enzymes. Under these conditions, a purification factor for CMCase and FPase of 10.89 and 0.65 was reached, respectively. The addition of inorganic salts changed the distribution of enzymes. Of these, CaCl2 contributed to a higher distribution coefficient (50.0), whereas for FPase, the presence of MnSO4 in the system improved the purification factor to 3.94.ConclusionThe highest values obtained for the yield and purification factors demonstrate that ATPMS is an interesting option for recovering and purifying cellulolytic enzymes.

Rhamnolipids biosurfactants as potential modulators of phase and partitioning behavior in micellar systems of aliphatic alcohol ethoxylate surfactants

Abstract The impact of rhamnolipids (RL) biosurfactants presence on the phase-separation equilibrium, micellar properties and partitioning behavior of systems containing the aliphatic non-ionic surfactant Tergitol 15-S-7 (Tg7) was studied in this work. The cloud points of Tg7 solutions (1‐ 10% w/w) in water and sodium citrate (NaCit) buffers pH 7.00 were increased after the RL addition (0.25% w/w) while they were decreased in NaCit pH 5.00. The most marked changes were verified for those systems with low Tg7 concentrations ( 7°). As expected, the zeta potential (ζ) of non-ionic Tg7 systems was close to zero; however, ζ became clearly negative (≅ −20 mV) in NaCit pH 7.00 after the addition of RL. This finding suggested that RL, which is negatively charged at pH 7.00, self-incorporated into Tg7 micelles and conferred them its charge. Hydrodynamic diameter (Dh) was either increased (in citrate media) or decreased (in water) by the RL, depending on the changes caused in the critical packing parameter of mixed micelles. Interestingly, an exponential decay equation, useful for predictive purpose, was found to correlate the cloud point with the hydrodynamic diameter, thus evidencing the crucial role of micelle size/shape on the phase separation. The partitioning behavior of cibacron blue (CB) and malaquite green (MG), negatively and positively charged dyes respectively, in Tg7 aqueous micellar two-phase systems (AMTPS) was significantly affected by the RL 0.25% w/w. In AMTPS with pH 7.00, the RL induced opposite effects, either duplicating the partition coefficient of MG or reducing it to a half for CB. Attractive and repulsive electrostatic interactions between the negatively charged mixed micelles and the partitioned molecules would be responsible of these trends. These results demonstrate the role of RL as a modulator of partitioning behavior of charged molecules and its potential use to improve recoveries and selectivity in a purification protocol.

Recyclable menthol-based deep eutectic solvent micellar system for extracting phytochemicals from Ginkgo biloba leaves

Abstract With an emphasis on human health, the demand for natural products is progressively increasing and sustainable extraction technologies for phytochemicals are receiving greater attention. In the present study, we established a naturally recyclable two-phase aqueous micellar system comprising menthol-based hydrophobic deep eutectic solvent (DES) in water. Typical representative phytochemicals from Ginkgo biloba leaves included flavonoid glycosides, terpene lactones, and bioflavonoids. These compounds have differing polarities and were selected as targets for the evaluation of our novel menthol-based aqueous DES as a green and sustainable extraction technology for partitioning various compounds. Components of the aqueous DES system and extraction process were systematically studied, and the following optimal conditions were identified: menthol–acetic acid ratio of 1:1 (mol/mol), DES–water ratio of 1:1 (v/v), solid–liquid ratio of 15:1 (mg/mL), extraction power of 200 W, and extraction time of 10 min. The two-phase system easily separated compounds with differing polarity into the upper (DES-rich phase) and lower (water phase) phases after extraction. Analyses of the related mechanisms indicated that micelle formation of menthol-based DES in water was the dominant separating process and that this process provided large contact areas between target compounds and extraction solvent, thereby promoting extraction from G. biloba leaves. Moreover, this aqueous DES system could efficiently be recovered and reused in regeneration studies. This novel menthol-based aqueous DES system provides a sustainable extraction technology for various phytochemicals from plant materials.

Use of Ionic Liquids as Cosurfactants in Mixed Aqueous Micellar Two-Phase Systems to Improve the Simultaneous Separation of Immunoglobulin G and Human Serum Albumin from Expired Human Plasma

A large fraction of unused clinical transfusion plasma is nowadays discarded. Nevertheless, some proteins, including serum albumin, immunoglobulins, and clot factors, are still viable for use in diagnosis or research. However, lasma is a complex matrix, requiring multiple steps and time-consuming methods for the isolation of proteins. In this work, aqueous micellar two-phase systems (AMTPS) composed of nonionic surfactants (Triton X-114 or Tergitol 15-S-7) were investigated to simultaneously separate immunoglobulin G (IgG) and human serum albumin (HSA) from human expired plasma. A factorial planning was applied to the nonionic surfactant and plasma concentrations to enhance the systems separation performance. After identifying the best conditions with AMTPS formed by nonionic surfactants, mixed AMTPS formed by Tergitol 15-S-7 and various surface-active ionic liquids (SAILs) acting as cosurfactants were additionally investigated to tailor the proteins partition between the two phases. The mixed AMTPS composed of Tergitol 15-S-7 as the nonionic surfactant and tributyltetradecylphosphonium chloride as the cosurfactant at pH 8.0 improved the simultaneous separation of both proteins to the opposite phases. IgG purification of 1.14-fold in the surfactant-poor phase and HSA purification of 1.36-fold in the surfactant-rich phase were obtained. Method reproducibility was investigated using additional samples of human serum and plasma and serum mixtures. Although improvements in the purification factor of each protein are still a future goal, mixed AMTPS comprising nonionic surfactants and SAILs as cosurfactants may be considered as novel platforms to be used in the simultaneous separation of value-added compounds from complex and natural matrices.

From single gemini surfactants in water to catanionic mixtures with the bile salt sodium taurodeoxycholate: Extensive micellar solutions, coacervation and liquid crystal polymorphism as revealed by phase behavior studies

Gemini surfactants and bile acid salts are interesting amphiphiles owing to their unconventional and versatile molecular structure, and consequent unusual aggregation properties. In this work, we investigated the phase behavior of binary surfactant/water systems for the cationic bis-quat gemini surfactants 12-2-12 (short spacer) and 12-6-12 (intermediate spacer) and subsequently catanionic mixtures of each gemini surfactant and the bile salt sodium taurodeoxycholate, STDC. The phase diagrams and phase structure were unraveled by polarized light microscopy, differential scanning calorimetry, deuterium NMR and small angle X-ray scattering. The 12-2-12 and 12-6-12 gemini form a micellar-lamellar-cubic and micellar-hexagonal-cubic phase sequence, respectively, denoting the strong influence of the spacer length on the self-assembly properties. Both the catanionic 12-2-12/STDC/water and 12-6-12/STDC/water systems display a rich mesomorphic behavior. One of the most striking features is that the STDC micelles are able to incorporate enormous amounts of gemini surfactant, forming an extremely wide solution region of mixed micellar structures. By contrast, the gemini micelles can only solubilize limited amounts of STDC. The liquid crystalline phases from the binary systems incorporate sizeable amounts of the counterpart surfactant, forming mixed catanionic aggregates at high concentration. Interestingly, the dilute region of both systems is dominated by liquid-liquid phase separation implying the formation of aqueous two-phase micellar systems. The observed features are qualitatively rationalized in terms of packing and electrostatic effects between the surfactants at play.

First Investigation of the Micelles Forming in a Novel Deep Eutectic Solvents-Based Aqueous Micellar Two-Phase System: Partitioning of Cationic/Neutral/Anionic Pigments

A novel aqueous micellar two-phase system (AMTPS) formed by two new types of PEG-based hydrophobic (acted as “cationic surfactant” or “nonionic surfactant”) and hydrophilic deep eutectic solvents (DESs) was first established. Three typical representative pigments, methylene blue (MB), Sudan III (Su), and sunset yellow FCF (SY) with diverse charge and hydrophobicity, were selected as the target to evaluate the possibility of the novel DES/DES-based AMTPS as a green extraction technology for partitioning various substances. The constitutions of AMTPS were systematically studied, including the effects of hydrophobic and hydrophilic DES types, molar ratio of choline chloride/glycerol, and molecular weights of PEG. After investigation, the DES/DES-based AMTPS was prepared with [N8881]Cl/PEG400 as hydrophobic DES and Ch/G (molar ratio 1:1) as hydrophilic DES. The concentration of pigments, ionic strength, pH value, and temperature were comprehensively evaluated in the influence factor experiments. Also, the res...

Integration of aqueous (micellar) two-phase systems on the proteins separation

A two-step approach combining an aqueous two-phase system (ATPS) and an aqueous micellar two-phase system (AMTPS), both based on the thermo-responsive copolymer Pluronic L-35, is here proposed for the purification of proteins and tested on the sequential separation of three model proteins, cytochrome c, ovalbumin and azocasein. Phase diagrams were established for the ATPS, as well as co-existence curves for the AMTPS. Then, by scanning and choosing the most promising systems, the separation of the three model proteins was performed. The aqueous systems based on Pluronic L-35 and potassium phosphate buffer (pH = 6.6) proved to be the most selective platform to separate the proteins (SAzo/Cyt = 1667; SOva/Cyt = 5.33 e SAzo/Ova = 1676). The consecutive fractionation of these proteins as well as their isolation from the aqueous phases was proposed, envisaging the industrial application of this downstream strategy. The environmental impact of this downstream process was studied, considering the carbon footprint as the final output. The main contribution to the total carbon footprint comes from the ultrafiltration (~ 49%) and the acid precipitation (~ 33%) due to the energy consumption in the centrifugation. The ATPS step contributes to ~ 17% while the AMTPS only accounts for 0.30% of the total carbon footprint.

Long-Chain Alcohol-Modified Micellar Systems and Their Application in a Continuous Extraction Process

The integration of an in situ extraction into biocatalytic processes is often limited by the toxicity of organic solvents. Therefore, it is desirable to use water-based extraction systems (for example, aqueous micellar two-phase systems). They can be used, for instance, for the extraction of valuable products from microalgae cultures. Recently, the nonionic surfactant ROKAnol NL5 was identified as a suitable surfactant for this purpose, since it forms an upper micellar phase, enabling an easy separation of whole-cell biocatalysts. However, its application at temperatures below 45 °C is limited by unstable phase boundaries, whereas the maximal temperature to ensure the vitality of the most microalgae cultures is ∼40 °C. To overcome this problem, the addition of long-chain alcohols to the surfactant–water mixture during extraction is suggested in this work. Using 1-hexanol, a continuous extraction process with the model solute trans-cinnamic acid at 40 °C in a stirred column could be realized. The results o...

Purification of a Bacteriocin-Like Inhibitory Substance Derived from Pediococcus acidilactici Kp10 by an Aqueous Micellar Two-Phase System.

Aqueous micellar two-phase system (AMTPS) is an extractive technique of biomolecule, where it is based on the differential partitioning behavior of biomolecule between a micelle-rich and a micelle-poor phase. In this study, an AMTPS composed of a nonionic surfactant, Triton X-100 (TX-100) was used for purifying a bacteriocin-like inhibitory substance (BLIS) derived from Pediococcus acidilactici Kp10. The influences of the surfactant concentration and the effect of additives on the partitioning behavior and activity yield of the BLIS were investigated. The obtained coexistence curves showed that the mixtures of solutions composed of different surfactant concentrations (5-30% w/w) and 50% w/w crude load were able to separate into two phases at temperatures of above 60 °C. The optimum conditions for BLIS partitioning using the TX-100-based AMTPS were: TX-100 concentration of 22.5% w/w, CFCS load of 50% w/w, incubation time of 30 min at 75 °C, and back-extraction using acetone precipitation. This optimal partitioning resulted in an activity yield of 64.3% and a purification factor of 5.8. Moreover, the addition of several additives, such as sorbitol, KCl, dioctyl sulfosuccinate sodium salt, and Coomassie® Brilliant Blue, demonstrated no improvement in the BLIS separation, except for Amberlite® resin XAD-4, where the activity yield was improved to 70.3% but the purification factor was reduced to 2.3. Results from this study have demonstrated the potential and applicability of TX-100-based AMTPS as a primary recovery method for the BLIS from a complex fermentation broth of P. acidilactici Kp10. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2719, 2019.