Aqueous Two-phase Extraction System Research Articles

Ultrasonication followed by aqueous two-phase system for extraction, on-site modification and isolation of microalgal starch with reduced digestibility

Microalgae are new and sustainable sources of starch with higher productivity and flexible production modes than conventional terrestrial crops, but the downstream processes need further development. Here, ultrasonication (with power of 200 W or 300 W and duration of 10, 15, 20, or 25 min) was applied to simultaneously extract and modify starch from a marine microalga Tetraselmis subcordiformis for reducing the digestibility, and an aqueous two-phase system (ATPS) of ethanol/NaH2PO4 was then used to isolate the starches with varied properties. Increasing ultrasonic duration facilitated the partition of starch into the bottom pellet, while enhancing the ultrasonic power was conducive to the allocation in the interphase of the ATPS. The overall starch recovery yield reached 73 ∼ 87 % and showed no significant difference among the ultrasonic conditions tested. The sequential ultrasonication-ATPS process successfully enriched the starch with purities up to 65 % ∼ 88 %, which was among the top levels reported in microalgal starch isolated. Ultrasonication produced more amylose which was mainly fractionated into the interface of the ATPS. The digestibility of the starch was altered under different ultrasonic conditions and varied from different ATPS phases as well, with the one under the ultrasonic power of 200 W for 15 min at the bottom pellet having the highest resistant starch content (RS, 39.7 %). The structural and compositional analysis evidenced that the ultrasonication-ATPS process could exert impacts on the digestibility through altering the surface roughness and fissures of the starch granules, modulating the impurity compositions (protein and lipid) that could interact with starch, and modifying the long- and short-range ordered structures. The developed ultrasonication-ATPS process provided novel insights into the mechanism and strategy for efficient production of functional starch from microalgae with a potential in industrial application.

Comparison of an Ultrasound-Assisted Aqueous Two-Phase System Extraction of Anthocyanins from Pomegranate Pomaces by Utilizing the Artificial Neural Network-Genetic Algorithm and Response Surface Methodology Models.

As a by-product of pomegranate processing, the recycling and reuse of pomegranate pomaces (PPs) were crucial to environmentally sustainable development. Ultrasound-assisted aqueous two-phase extraction (UA-ATPE) was applied to extract the anthocyanins (ACNs) from PPs in this study, and the central composite design response surface methodology (CCD-RSM) and artificial neural network-genetic algorithm (ANN-GA) models were utilized to optimize the extraction parameters and achieve the best yield. The results indicated that the ANN-GA model built for the ACN yield had a greater degree of fit and accuracy than the RSM model. The ideal model process parameters were optimized to have a liquid-solid ratio of 49.0 mL/g, an ethanol concentration of 28 g/100 g, an ultrasonic time of 27 min, and an ultrasonic power of 330 W, with a maximum value of 86.98% for the anticipated ACN yield. The experimental maximum value was 87.82%, which was within the 95% confidence interval. A total of six ACNs from PPs were identified by utilizing UHPLC-ESI-HRMS/MS, with the maximum content of cyanidin-3-O-glucoside being 57.01 ± 1.36 mg/g DW. Therefore, this study has positive significance for exploring the potential value of more by-products and obtaining good ecological and economic benefits in the future.

Structure of polyethylene glycol/water mixtures as a separation medium of aqueous two-phase extraction systems studied by equilibrium analysis of thiocyanato complexation of Cobalt(II)

Aqueous two-phase systems (ATPS) utilizing polyethylene glycol (PEG) have been successfully used for the separation of various organic and inorganic compounds as an environmentally benign extraction method. However, a fundamental understanding of the role of the hydration structures around PEG chains in solute partitioning in ATPS remains elusive although it has been considered that PEG molecules are involved in separation. In the present work, the equilibria of Co(II) thiocyanate complexation reaction in aqueous PEG solutions were studied by spectrophotometry with varying ethylene oxide chain length and concentration of PEG. From the formation constants of the tetrahedral and octahedral Co(II) thiocyanate complexes obtained, a microheterogeneous structure consisting of pseudo phases formed by hydration of ethylene oxide (EO) chain and terminal hydroxyl (OH) groups in the PEG molecule in addition to the bulk water phase was estimated. It was revealed that the formation of tetrahedral Co(NCS)42− complex proceeds in the EO pseudo phase by the involvement of hydrophobic ethylene groups, while the OH phase and the bulk phase inhibit the progress of the reaction. This indicates that Co(NCS)42− is stable in hydrophobic hydration structure of water around the EO moiety. The EO phase imparts hydrophobicity to aqueous PEG solutions and plays a predominant role in partition of solute molecules in PEG-based ATPS.

Extraction of collagenolytic proteases from Aspergillus heteromorphus URM 0269 in an aqueous two-phase system for application in collagen hydrolysis

Collagenolytic proteases produced by Aspergillus heteromorphus URM0269 were extracted using a PEG/sulfate aqueous two-phase system (ATPS). A 23 factorial design was performed to analyze the independent variables: PEG molar mass (MPEG), PEG concentration (CPEG), and sulfate concentration (Csulf). The extracted proteases were also evaluated for their optimum pH and stability at different pH levels (4.0 − 11.0) after 20 h of incubation. Collagen was extracted from mutton snapper (Lutjanus analis) skin using acetic acid (0.5 mol L−1). The enzyme was preferentially partitioned to the PEG-rich phase (K > 1), whose highest purification factor and recovery (PF = 6.256 and Y = 404.432%) were obtained under specific conditions: MPEG 8000 g.mol−1, CPEG 30%, Csulf 10%. The ATPS extraction provided an enzymatic activity range of pH 7.0 − 11.0, exhibiting greater stability compared to the crude extract. Approximately 80% of protease activity was maintained after 20 hours of incubation at all analyzed pH levels, except pH 11.0. Collagen extraction from L. analis skin yielded 8.056%, and both crude extract samples and ATPS-derived samples successfully hydrolyzed the extracted collagen, reaching peak hydrolysis after 36 hours of treatment. These findings demonstrate the feasibility of extracting highly purified and active proteases capable of hydrolyzing L. analis collagen.

Computational investigation on the molecular driving forces for extraction of Co2+, Ni2+, and Fe3+ in poly(ethylene oxide)/thiocyanate salt aqueous two-phase systems

Aqueous two-phase systems are environmentally friendlier alternatives for hydrometallurgical processing and purification of metals. However, the viability of application of those systems in such processes is still under investigation, in which the comprehension of the fundamental aspects that govern the metal extraction is essential and can be further constructed using computational approaches. This research paper presents a comprehensive computational study on the fundamental nature of metal extraction in polymer-salt aqueous two-phase systems (ATPS), comparing the results of modeling and simulation work to the theoretical and experimental data available in the literature. Specifically, the mechanisms underlying the extraction of Co2+, Ni2+, and Fe3+, in ATPS formed by poly(ethylene oxide) (PEO) and thiocyanate salt are investigated, using quantum chemical calculations and molecular dynamics simulations. The formation of pseudo-polycations (PPCs) and thiocyanate metalates (complexes formed by a metal cation bonded to one or more anions) and the interaction of PEO fragments, thiocyanate, and aquo ligands with metal cations are explored. The binding affinity of these species is evaluated from various perspectives, including structural, electronic, and thermodynamic considerations. The solvation behavior of the species in solvents with different polarities is also examined. The findings elucidate the mechanisms governing metal cations partitioning behavior in PEO/thiocyanate ATPS, confirming the mechanisms proposed previously in the literature, involving charge transfer between metal-thiocyanate complexes and polyethylene oxide ether groups as well as interactions between metalate and PPCs. This study represents the first-ever computational investigation into the molecular driving forces behind metal extraction in polymer-salt ATPS, providing valuable insights for optimizing extraction processes and paving the way for future research in this field.

Ethanol/salt aqueous two‐phase systems (ATPS) for enrichment and identification of bioactive constituents escaping during pectin extraction

SummaryThe acid heating extraction process is commonly employed to extract pectin from citrus peels, which results in the leaching of bioactive constituents into solvents. However, the discharge of these solvents represents a significant loss of valuable resources. To address this issue, this study aims to identify the composition and concentration of the bioactive constituents that escape into the solvents and propose an extraction process based on an ethanol‐salt aqueous two‐phase system (ATPS). The well‐designed ATPS enables the enrichment and recovery of the bioactive constituents, and the findings demonstrate that the ethanol/sodium citrate‐based ATPS can recover up to 80.61% of limonoids, 84.11% of flavonoids, and 88.09% of polyphenols that escape at an enrichment efficiency of 50.00%. Moreover, HPLC‐DAD and UPLC‐HRMS analysis of the ATPS extracts revealed the presence of nine bioactive constituents, including flavonoids, phenolic acids, and limonoids. Remarkably, in vitro antioxidant capacity studies indicate that the ATPS extracts exhibit superior antioxidant activity compared to the vacuum‐concentrated solution. Thus, these results suggest that the application of ATPS extraction is a feasible and promising strategy for the recovery of bioactive constituents.

A sulfonated ligand-aqueous two-phase system for selective extraction of thorium from mining wastewater: Process optimization, structural characterization and mechanism exploration

As a potential nuclear fuel, the recovery of thorium with high efficiency, high selectivity and high extraction capacity from thorium-containing wastewater is considered to be one of the effective ways to reduce pollution and solve the shortage of thorium resources. However, the problem of efficient and selective separation of thorium from the complex environment has not been completely solved. Herein, a functional ligand called arsenazo (ASA), polyethylene glycol, and sodium sulphate were used to construct an aqueous two-phase system (ATPs) for the selectivity extraction and separation of thorium from mining wastewater. Furthermore, the complex agent, pH value, temperature, equilibrium time, coexisting substances, and other conditions for the extraction and separation of thorium were optimized, indicating that 98.7 % of thorium was efficiently and precisely separated from the acid-leaching solution to the pH of 2–3 or 5–6 with 0.08 g/L of ASA within 10 min, and the interference with multiple coexisting ions and organic substances was avoided. Importantly, the analysis of water quality parameters, thermogravimetry, infrared spectroscopy, and ultraviolet–visible spectroscopy revealed the coordination relationship between thorium ions and complex agents, indicating that the extraction of thorium in the aqueous two-phase system was a cation exchange mechanism. More importantly, SEM, TEM, EDX, and XRD verified that thorium was efficiently and selectively separated by a sulfone acid ligand-aqueous two-phase system, providing quantitative information on thorium-containing product distribution of relatively high accuracy and avoiding the interference with coexisting substance. Therefore, this work provided theoretical guidance on treating and reusing thorium in wastewater and enriched the content of functional ligand-aqueous two-phase extraction systems in green production technology.

Highly-Selective Harvesting of (6,4) SWCNTs Using the Aqueous Two-Phase Extraction Method and Nonionic Surfactants.

Monochiral single-walled carbon nanotubes (SWCNTs) are indispensable for advancing the technology readiness level of nanocarbon-based concepts. In recent times, many separation techniques have been developed to obtain specific SWCNTs from raw unsorted materials to catalyze the development in this area. This work presents how the aqueous two-phase extraction (ATPE) method can be enhanced for the straightforward isolation of (6,4) SWCNTs in one step. Introducing nonionic surfactant into the typically employed mixture of anionic surfactants, which drive the partitioning, is essential to increasing the ATPE system's resolution. A thorough analysis of the parameter space by experiments and modeling reveals the underlying interactions between SWCNTs, surfactants, and phase-forming agents, which drive the partitioning. Based on new insight gained on this front, a separation mechanism is proposed. Notably, the developed method is highly robust, which is proven by isolating (6,4) SWCNTs from several raw SWCNT materials, including SWCNT waste generated over the years in the laboratory.

Aqueous two-phase extraction: A non-thermal technique to separate and concentrate betalains from Bougainvillea glabra Choisy bracts

The purple bracts of Bougainvillea glabra Choisy contain betalains that can be used as pigmenting agents. The objective was to evaluate the use of aqueous two-phase extraction systems to separate betalains from B. glabra bracts in order to improve the potential of this species as a source of natural pigments. A binodal phase diagram for the mixture of polyethylene glycol 4000 (PEG 4000) and trisodium citrate (Na3Cit; Na3C6H5O7) was studied to select betalain extraction conditions. The separation and concentration of betalains was evaluated and the feasibility of partitioning into betacyanins and betaxanthins was assessed. Mixtures of Na3Cit and PEG 4000 were prepared with concentrations in the ranges of 3.02–39.69% and 0.28–36.98%, respectively, and formed aqueous biphasic systems, with top phases composed mainly by PEG 4000 and bottom phases composed mainly by Na3Cit. The betalains showed a tendency to migrate towards the top phase, with an average separation yield of 92.41% and a concentration of 176.57 mg/L, while in the bottom phase an average content of 4.53 mg/L was found. Such situation was caused by a salting-out phenomenon and by a non-thermal concentration of compounds given by a reduction of the volume ratio between phases. The partition coefficient varied between 18.95 and 183.4 in betacyanins (Bc) and between 6.85 and 80.0 in betaxanthins (Bx). The Bc/Bx ratio varied between 2.82 and 3.26 in top phases and between 1.26 and 1.45 in bottom phases. The use of aqueous two-phase extraction systems allowed betalains to be separated and concentrated, although only a partial partitioning of Bc and Bx was achieved.

Understanding the partitioning behavior of single-walled carbon nanotubes using an aqueous two-phase extraction system composed of non-ionic surfactants and polymers.

In this work, a Pluronic/Dextran system was developed to discover the mechanism of the aqueous two-phase extraction (ATPE) technique, which is widely employed for the sorting of single-walled carbon nanotubes (SWCNTs) and other types of nanomaterials. The role of the phase-forming components and partitioning modulators was comprehensively investigated to gain greater insights into the differentiation process. The obtained results revealed that sodium dodecyl sulfate and sodium dodecylbenzene sulfonate operated as excellent partitioning modulators, enabling the diameter-based sorting of SWCNTs. Additionally, the data strongly suggested that different densities of various SWCNT species drove the movement of SWCNTs in the ATPE system. Consequently, the largest diameter SWCNTs were first influenced by surfactants and, thus, the nanotubes migrated towards a lower density top phase in the following order (7,5) > (8,3) > (6,5) > (6,4). Based on the in-depth analysis of the partitioning system, a mechanism was proposed that described the method in which the popular ATPE separation technique operates.

A novel procedure for simultaneous extraction of polysaccharides and polyphenols from Schisandra Chinensis: Modeling, characterization and biological properties

High pressure assisted aqueous two-phase system for simultaneous extraction of polysaccharides and polyphenols from Schisandra chinensis was modeled by response surface methodology (RSM) and artificial neural network (ANN). ANN displayed higher coefficient of determination (0.9725), and lower Pearson’s Chi-square (0.2950), absolute average deviation (1.0693) and root means square error (0.6479) than RSM model (0.9440, 0.6231, 1.6725, 0.9666), indicating ANN had better prediction capability than RSM. Under suitable aqueous two-phase system (ethanol/ammonium sulfate, 29.37%/19.83%) combining with optimal high pressure conditions (liquid-to-material ratio 87.10 mL/g, pressure 4.78 MPa, temperature 60.92 °C, and time 16.01 min) predicted by ANN, the yields of polyphenols, polysaccharides, and DPPH radical scavenging activities were separately 1.87 ± 0.06 mg/g, 16.76% ± 0.52%, 95.04% ± 0.97% and 84.84% ± 1.48%, which were higher than the response values optimized by RSM (1.80 ± 0.60 mg/g, 16.19%±0.37%, 91.28% ± 1.92%, 83.19% ± 0.97%). After purification by column chromatography, the polyphenols in top phase (SCTP) and polysaccharides in bottom phase (SCBP) were obtained. Rutin, hyperoside, quercetin and veronicastroside were the main phenolic compounds in SCTP, which displayed strong antibacterial effects against foodborne pathogens. SCBP was an acidic heteropolysaccharide with a molecular weight of 6.46 × 106 g/mol, and showed potent protective effects against erythrocyte hemolysis.

Simultaneous Prediction, Determination, and Extraction of Four Polycyclic Aromatic Hydrocarbons in the Environment Using a UCON-NaH2PO4 Aqueous Two-Phase Extraction System Combined with High-Performance Liquid Chromatography-Ultraviolet Detection.

In this paper, a new aqueous two-phase extraction system(ATPES) consisting of UCON (poly(ethylene glycol-ran-propylene glycol) monobutyl ether)–NaH2PO4 was established, and four trace polycyclic aromatic hydrocarbons (PAHs: fluorene, anthracene, pyrene and phenanthrene) in water and soil were analyzed by high-performance liquid chromatography (HPLC)–ultraviolet detection. In the multi-factor experiment, the central composite design (CCD) was used to determine the optimum technological conditions. The final optimal conditions were as follows: the concentration of UCON was 0.45 g·mL−1, the concentration of NaH2PO4 was 3.5 mol·L−1, and the temperature was 30 °C. The recovery of the four targets was 98.91–99.84% with a relative standard deviation of 0.3–2.1%. Then UCON recycling and cyclic tests were designed in the experiment, and the results showed that the recovery of PAHs gradually increased in the three extractions because of the remaining PAHs in the salt phase of last extraction. The recovery of PAHs in the UCON recycling test was less than that in the extraction test due to the wastage of UCON. In addition, a two-phase aqueous extraction model was established based on the random forest (RF) model. The results obtained were compared with the experimental data, and the root mean square error (RMSE) was 0.0371–0.0514 and the correlation coefficient R2 was 96.20–98.53%, proving that the model is robust and reliable.

Separation and Purification of Astragalus membranaceus Polysaccharides by Deep Eutectic Solvents-Based Aqueous Two-Phase System.

(1) Background: Aqueous two-phase systems (ATPSs) have been widely used in the separation and purification of bioactive substances in recent years. (2) Methods: In this study, deep eutectic solvents (DESs)-based ATPSs were employed for the extraction and separation of Astragalus membranaceus polysaccharides (AMP). The optimal DES (choline chloride:urea = 1:1) was first screened to extract AMP, and the effect of DES concentration, solid–liquid ratio, pH, extraction temperature, and extraction time on the extraction yield of AMP were investigated. (3) Results: The maximum extraction yield was 141.11 mg/g under the optimum conditions. AMP was then preliminarily purified by ATPS, to further realize the recycling and reuse of DES. The effect of type of salts, salt concentration, and extraction temperature on extraction efficiency was investigated. The extraction efficiency was 97.85% for AMP under the optimum ATPS conditions. Finally, the obtained AMP was studied by molecular weight determination, infrared spectroscopy analysis, and monosaccharide composition analysis. (4) Conclusions: This ATPS extraction based on DESs is simple, environmentally friendly, low-cost, and has high extraction efficiency, which provides new ideas for the extraction of plant polysaccharides and other bioactive compounds.

Amoxicillin removal from medical wastewater using an eco-friendly aqueous two-phase extraction system

ABSTRACT Antibiotics are a common medical waste that can cause antibiotic resistance in humans and harm aquatic life. One of the most effective approaches for treating medical wastewater is the aqueous two-phase extraction process (ATPS). ATPS is considered an ecologically benign technology. Nine ATPS chemical systems were developed to extract Amoxicillin from simulated hospital wastewater using various salts and organic solvents. The criteria that determine the most efficient system were explored in order to maximize the separation process. After assessing the performance of the considered systems, amoxicillin extraction was carried out utilizing an ATPS comprised of PEG6000 as an extractant and K2HPO4 as a separating agent. Complete amoxicillin removal was attained at room temperature and a mixing speed of 500 rpm for 540 mins. The extraction efficiency was found to increase with temperature, salt concentration, and the volume ratio of the solvent (PEG6000). Based on the experimental design methodology, the optimum amoxicillin removal efficiency of 96.4% was attained at a temperature of 44.3°C, 42.6 wt.% of salt, and a 0.5 volume fraction ratio of PEG6000. The stagewise application of the process was also performed within five separation stages. This approach outperforms traditional extraction methods in terms of efficacy and duration.

Comparison of Extraction Methods and Extraction Optimization in Aqueous Two-Phase System for Ethyl Carbamate Analysis in Model Systems for Maesil Wine

Ethyl carbamate (EC) is a known carcinogen, and therefore its intake is regulated internationally. The objectives of this study were to compare the EC recovery yields under different liquid-liquid extraction (LLE) conditions and to investigate the optimum conditions of the aqueous two-phase system (ATPS) for EC extraction. Our results showed that for the LLE method, addition of 15% NaCl improved the EC yield by 15%, and dichloromethane as the extraction solvent showed a slightly higher yield (about 5%) than chloroform. However, there was little difference in the yield when mixing was performed using an ultrasonic bath compared to a vortex mixer. Using response surface methodology with central composite design to analyze the ATPS results, optimal extraction was found to occur at 21.5°C for 2.8 h in the sample containing 70% alcohol and 15% phosphate, showing a recovery yield of 75.64%. This information can be applied to alcoholic beverages and other fermented food products to analyze EC with better extraction methods, depending on the types of food.

Biological production and recovery of 2,3-butanediol using arabinose from sugar beet pulp by Enterobacter ludwigii

Sugar beet pulp (SBP) is a major byproduct from the sugar industries and consists of >20% w/w arabinose. The current work evaluated the potential of Enterobacter ludwigii assimilating pure arabinose and arabinose rich hydrolysate from SBP pellets for 2,3-butanediol (BDO) production. The hydrolysate was obtained through dilute acid pretreatment (DAP) with sulphuric acid. The process was optimized for acid and solid loading to obtain a hydrolysate free from furan derivatives. The effect of different levels of substrate (10–60 g/L) using pure arabinose was conducted in shake flask experiments, followed by co-fermentation with small amounts of glucose and SBP hydrolysate. After flask cultivations, BDO fermentations were carried-out in a bench-top bioreactor in batch and fed-batch modes using pure arabinose as well as SBP hydrolysate. The fed-batch culture led to BDO production of 42.9 and 35.5 g/L from pure arabinose and SBP hydrolysate with conversion yields of 0.31 and 0.29 g/g, respectively. Finally, BDO accumulated on pure arabinose and SBP hydrolysate were recovered using an aqueous two-phase extraction system. The recovery yield of BDO accumulated on arabinose and hydrolysate was ∼97%. The work demonstrated the feasibility of using SBP as a suitable feedstock for manufacturing BDO.

Probing Liquid-Liquid Phase Separation in Secondary Organic Aerosol Mimicking Solutions Using Articulated Straws.

The presence or absence of liquid–liquid phase separation (LLPS) in aerosol particles containing oxidized organic species and inorganic salts affects particle morphology and influences uptake into, diffusion through, and reactivity within those particles. We report here an accessible method, similar to ice core analyses, using solutions that are relevant for both aerosol chemical systems and aqueous two-phase extraction systems and contain ammonium sulfate and one of eight alcohols (methanol, ethanol, 1-propanol, 2-propanol, 2-butaonol, 3-methyl-2-butanol, 1,2-propanediol, or 1,3-propanediol) frozen in articulated (bendable) straws to probe LLPS. For alcohols with negative octanol–water partitioning coefficient (KOW) values and O/C ratios ≥0.5, no LLPS occurs, while for alcohols with positive KOW values and O/C ratios ≤0.33, phase separation always occurs, both findings consistent with observations using different experimental techniques. When a third species, glyoxal, is added, the glyoxal stays in the aqueous phase, regardless of whether LLPS occurs. When phase separation occurs, the glyoxal forms a strong intermolecular interaction with the sulfate ion, red-shifting the ν3(SO42–) peak by 15 cm–1. These results provide evidence of chemical interactions within phase-separated systems that have implications for understanding chemical reactivity within those, and related, systems.

Separation of recombinant monoclonal antibodies IgG201 from a cell culture supernatant using an integrated aqueous two-phase system with thermo-separating EOPO

The purification of monoclonal antibodies IgG201 produced in Chinese hamster ovary cells was accomplished by aqueous two-phase system (ATPS) extraction. Host cell proteins, pigments, and other impurities were removed during ATPS extraction. Two simulation modules, Blends and Dissipative particle dynamics (DPD), from Material Studio software, were innovatively applied to investigate the mechanisms of antibody extraction using ATPS. The simulation results indicated that antibodies were extracted from the cell culture supernatant into the EOPO polymer phase at a pH close to or higher than its isoelectric point, while antibodies were transferred from the EOPO phase to the water phase at a pH much lower than its isoelectric point. In addition, the feasibility of using an EOPO polymer to extract monoclonal antibodies from a cell culture supernatant was investigated at different pH, compositions, and EOPO polymer contents. In the forward-extraction ATPS, a monoclonal antibody was extracted from the cell culture supernatant to the EO20PO80 polymer phase at pH 9. In the subsequent back-extraction ATPS, the monoclonal antibody was transferred to the water phase at pH 5.

Subcritical Ethanol-Water and ionic liquid extraction systems coupled with multi-frequency ultrasound in the extraction and purification of polysaccharides

ABSTRACT This study obtained crude sorghum leaf sheath polysaccharide (39.99% wet matter (wm)) by subcritical ethanol-water (40% v/v) extraction (180°C, 40 min). The subcritical extraction solution was transformed into an ionic liquid aqueous two-phase extraction system and subsequently coupled with ultrasound extraction to obtain partially purified polysaccharides (PPP). PPP yields of 20.89%, 27.38%, and 36.49% (wm) were obtained using 60 kHz, 20/60 kHz, and 20/40/60 kHz ultrasound frequencies, respectively. Polysaccharide functional groups such as hydroxyl, aldehyde, and amide were detected using Fourier Transform Infrared Spectroscopy (FT-IR). Amylose contents of 15%, 18%, and 25% were obtained for PPP under single, dual, and tri-frequencies, respectively. Amylose contents were associated with aggregation of PPP particles sizes after heat exposure (70°C for 1 h 50 min). Triple-frequency extracted polysaccharides with the highest uronic acid (1.51%) and polyphenolic (27.79%) contents had an IC50 of 1.37 mg/mL in an in-vitro hydroxyl scavenging activity assay. Three interesting co-extracted bioactive phytochemicals; 2-amino-5[(2-carboxy)vinyl]-Imidazole, N-[4-bromo-n butyl]-2-Piperidinone, and 3-Trifluoroacetyl Pentadecane were detected. The PPP extract showed antioxidant activity and contained phytochemicals with potential antimicrobial and antiviral activities, and thus may be useful in food, nutraceutical, and pharmaceutical applications.

High yield recovery of 2,3-butanediol from fermented broth accumulated on xylose rich sugarcane bagasse hydrolysate using aqueous two-phase extraction system

Downstream processing of chemicals obtained from fermentative route is challenging and cost-determining factor of any bioprocess. 2,3-Butanediol (BDO) is a promising chemical building block with myriad applications in the polymer, food, pharmaceuticals, and fuel sector. The current study focuses on the recovery and purification of BDO produced (68.2 g/L) from detoxified xylose-rich sugarcane bagasse hydrolysate by a mutant strain of Enterobacter ludwigii. Studies involving screening and optimization of aqueous-two phase system (ATPS) revealed that 30% w/v (NH4)2SO4 addition to clarified fermented broth facilitated BDO extraction in isopropanol (0.5 v/v), with maximum recovery and partition coefficient being 97.9 ± 4.6% and 45.5 ± 3.5, respectively. The optimized protocol was repeated with unfiltered broth containing 68.2 g/L BDO, cell biomass, and unspent protein, which led to the partitioning of 66.7 g/L BDO, 2.0 g/L xylose and 9.0 g/L acetic acid into organic phase with similar BDO recovery (97%) and partition coefficient (45).