scholarly journals Partitioning optimization of proteins from Zea mays malt in ATPS PEG 6000/CaCl2

2007 ◽  
Vol 50 (3) ◽  
pp. 557-564 ◽  
Author(s):  
Graziela Batista Ferreira ◽  
Alex Ferreira Evangelista ◽  
João Baptista Severo Junior ◽  
Roberto Rodrigues de Souza ◽  
José Carlos Curvelo Santana ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Partition Coefficient ◽  
Line Length ◽  
Purification Step ◽  
Two Phase ◽  
Peg 6000 ◽  
The Stability ◽  
The Relationship ◽  
Influence Of Ph ◽  
Tie Line

This work aimed to establish the relationship between the compositions and pH of ATPS PEG 6000/CaCl2 and the proteins partition from maize malt and also to simplify the process optimization in ATPS for a statistical model, established by response surface methodology (RSM). Results showed that these were no influence of pH on the phase diagrams and on the composition of tie line length of PEG 6000/CaCl2 ATPS. SRM analyses showed that elevated pH and larger tie line length were the best conditions for recovering of maize malt proteins. The maximum partition coefficient by PEG 6000/CaCl2 ATPS was about 4.2 and was achieved in ATPS in a single purification step. The theoretical maximum partition coefficient was between 4.1-4.3. The process was very suitable for continuous aqueous two-phase purification due to the stability of proteins (e.g. and -amylases) and could increase their content into middle.

scholarly journals The effect of sulphates on partitioning of pectinases in aqueous two-phase systems

2004 ◽  
pp. 179-186 ◽  
Author(s):  
Mirjana Antov ◽  
Draginja Pericin ◽  
Biljana Trbojevic
Keyword(s):  
Polyethylene Glycol ◽  
Partition Coefficient ◽  
Ammonium Sulphate ◽  
Line Length ◽  
Sodium Sulphate ◽  
Two Phase ◽  
Aqueous Two Phase Systems ◽  
Phase Systems ◽  
Sulphate Salts ◽  
Tie Line

The effect of various sulphate salts on the partitioning of endo-pectinase and exo-pectinase in aqueous two-phase systems, composed of polyethylene glycol and dextran, was studied. Presence of ammonium sulphate and sodium sulphate at concentration 15 mmol/l in the system polyethylene glycol 4000/crude dextran, at tie-line length 7.44%, increased partition coefficient of endo-pectinase 1.25 and 1.2 fold, respectively. Ammonium sulphate at 15 mmol/l and sodium sulphate at 5 mmol/l enhanced partition coefficient for exo-pectinase for about 60% in comparison to the system without salts. Addition of magnesium and sodium sulphate to a final concentration of 0.3 mmol/l in the system containing polyethylene glycol 6000/dextran 500 000, at tie-line length 6.26%, increased the partition coefficient of endo activity for 95% and 32%, respectively. Both salts at the same concentration increased partition coefficient of exo activity 1.5 and 3 times, respectively, in comparison to the system without salts.

scholarly journals Extraction of tetracycline using the ionic liquid-based aqueous two phase systems: Single-stage versus multi-stage

2018 ◽  
Vol 24 (4) ◽  
pp. 387-397 ◽  
Author(s):  
Yi Liu ◽  
Li Chen ◽  
Jun Zhou ◽  
Zongcheng Yan
Keyword(s):  
Extraction Efficiency ◽  
Ph Value ◽  
Influence Factors ◽  
Volume Ratio ◽  
Line Length ◽  
Single Stage ◽  
Two Phase ◽  
Extraction Behavior ◽  
Multi Stage ◽  
Tie Line

Ionic liquids-based aqueous two-phase extraction (ILs-ATPE) offers an alternative approach to the extraction of tetracycline (TC) through their partitioning between two phases. Single-stage and multi-stage strategies have been evaluated and compared for the purification of TC using ATPE composed of 1-butyl-3-methylimidazolium halide ([Bmim]X(X=Cl,Br)) and K2HPO4. The influence factors on single-stage extraction behavior of TC were optimized systematically, including the pH value, tie line length, and volume ratio. The optimal extraction efficiency of TC could reach above 95% when the volume ratio is higher than 1.5 and the tie line length is 30.52%. The multi-stage ATPE was also investigated by simulating a three-stage crosscurrent operation in test tubes. According to the TC isotherm curve and respective McCabe?Thiele diagrams, a predicted optimized scheme of the countercurrent multi-stage ATPE was determined. TC can be purified in the IL-rich top phase with a final extraction efficiency of 99% and a final TC concentration of 0.25 mg/mL, if a three- -stage [Bmim]Cl-K2HPO4 ATPE with volume ratio of 0.5 and tie line length of 30.52% was employed. Thus, the multi-stage extraction with small volume ratio is necessary to achieve a higher recovery yield, resulting in the reduction of the IL consumption.

scholarly journals Phase Separation Behavior and System Properties of Aqueous Two-Phase Systems with Polyethylene Glycol and Different Salts: Experiment and Correlation

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Haihua Yuan ◽  
Yang Liu ◽  
Wanqian Wei ◽  
Yongjie Zhao
Keyword(s):  
Phase Separation ◽  
Sodium Citrate ◽  
Line Length ◽  
Continuous Phase ◽  
Two Phase ◽  
Separation Rate ◽  
Aqueous Two Phase Systems ◽  
Phase Systems ◽  
System Properties ◽  
Tie Line

The phase separation behaviors of PEG1000/sodium citrate, PEG4000/sodium citrate, PEG1000/ammonium sulfate, and PEG4000/ammonium sulfate aqueous two-phase systems were investigated, respectively. There are two distinct situations for the phase separation rate in the investigated aqueous two-phase systems: one state is top-continuous phase with slow phase separation rate and strong bottom-continuous phase with fast phase separation rate and weak volume ratio dependence. The system properties such as density, viscosity, and interfacial tension between top and bottom phases which have effects on the phase separation rate of aqueous two-phase systems were measured. The property parameter differences between the two phases increased with increasing tie line length and then improved the phase separation rate. Moreover, a modified correlation equation including the phase separation rate, tie line length, and physical properties of the four aqueous two-phase systems has been proposed and successfully tested in the bottom-continuous phase, whose coefficients were estimated through regression analysis. The predicted results of PEG1000/sodium citrate aqueous two-phase systems were verified through the stationary phase retention in the cross-axis countercurrent chromatography.

scholarly journals Optimization of Aqueous Two-Phase System (ATPS) of Recombinant Bromelain by Response Surface Methodology

2018 ◽  
Vol 7 (4.30) ◽  
pp. 377
Author(s):  
Zatul Iffah Mohd Arshad ◽  
Azura Amid
Keyword(s):  
Response Surface Methodology ◽  
Enzyme Activity ◽  
Partition Coefficient ◽  
Response Surface ◽  
Potassium Phosphate ◽  
Phase System ◽  
Two Phase ◽  
Aqueous Two Phase System ◽  
Crude Sample ◽  
Face Centered

Recombinant bromelain is a protease that was partially purified using aqueous two-phase system (ATPS). The process variables (pH, PEG 6000 and potassium phosphate concentration) were optimized on enzyme activity and partition coefficient using response surface methodology (RSM) based on a face-centered central composite design (FCCCD) model. The optimum conditions for purification were at 18.47% [w/w] PEG6000 and 13% [w/w] potassium phosphate, pH 7.0 with enzyme activity was obtained as 0.272±0.0036 unit m/L, and partition coefficient as 1.394±0.093. The recombinant bromelain was preferentially partitioned into the top phase and the band was reduced in contrast to crude sample on SDS-PAGE gel.

scholarly journals Partitioning of cerrena unicolor laccase activity in an aqueous two-phase system

2016 ◽  
Vol 37 (2) ◽  
pp. 269-280 ◽  
Author(s):  
Michał Blatkiewicz ◽  
Axel Prinz ◽  
Andrzej Górak ◽  
Stanisław Ledakowicz
Keyword(s):  
Volume Ratio ◽  
Line Length ◽  
Bottom Phase ◽  
Phase System ◽  
Phase Volume ◽  
Two Phase ◽  
Aqueous Two Phase System ◽  
Phase Volume Ratio ◽  
Cerrena Unicolor ◽  
Tie Line

Abstract Culture supernatant containing laccase produced by Cerrena unicolor strain was used to examine laccase partitioning between phases in an aqueous two-phase system. The investigated system consisted of polyethylene glycol 3000 and sodium phosphate buffer adjusted to pH = 7. Influence of several parameters on partitioning was measured, including phase forming components’ concentrations, tie line lengths, phase volume ratio, supernatant dilution, process temperature and halogen salt supplementation. Partitioning coefficients up to 78 in the bottom phase were achieved with yields of over 90%. Tie line length and phase volume ratio had significant effect on enzyme partitioning.

scholarly journals Optimisation of LS54/Dx Aqueous Two Phase System Conditions for Cutinase Recovery

2013 ◽  
Vol 12 (2) ◽  
pp. 61
Author(s):  
Jamaliah Md. Jahim ◽  
Abdul Wahab Mohamad ◽  
Fariza Akmal Abdul Mutalib ◽  
Farah Diba Abu Bakar ◽  
Osman Hassan
Keyword(s):  
Recovery Process ◽  
Line Length ◽  
Phase System ◽  
Two Phase ◽  
Rich Phase ◽  
Aqueous Two Phase System ◽  
System Composition ◽  
Protein Partitioning ◽  
Tie Line ◽  
Positive Electrostatic Potential

Aqueous two phase system comprising Dehypon® LS 54 and K4484 Dextrin® was selected for recovery of cutinase enzyme. Parameters such as pH, system composition and type of salt as an additive, influenced the protein partitioning behaviour and optimisation of these parameters become necessary to be done in the design of primary recovery process of ATPS. The cutinase partitioning experiments were carried out with 30% of cutinase solution added to LS 54/Dx system. Results showed that cutinase enzyme preferred to partition into LS 54 rich-phase at pH 8.0 and the affinity of cutinase into top phase was observed higher with the increment of system compositions, which represented by tie line length (TLL). Furthermore, the addition of 50mM salts such as K2SO4 and KCl into LS 54/Dx system has led to raise partition coefficient of cutinase, kcut to 2.2 and 1.95 fold, respectively. The dependence of kcut on various additives such as (NH4)2SO4, Na2SO4 and K2SO4 at the same concentration, suggested that the addition of selected ions could enhance positive electrostatic potential which could attract more cutinase to partition into LS54 rich phase. As conclusion, the best conditions obtained for cutinase partitioning were pH8.0, TLL = 23% and Na2SO4 = 50mM, from which the maximum kcut of 2.83 with improved recovery of cutinase in top phase up to 79% can be achieved.

Cell Separation in Aqueous Two-Phase Systems − Influence of Polymer Molecular Weight and Tie-Line Length on the Resolution of Five Model Cell Lines

2017 ◽  
Vol 13 (2) ◽  
pp. 1700250 ◽  
Author(s):  
Sarah Zimmermann ◽  
Sarah Gretzinger ◽  
Philipp K. Zimmermann ◽  
Are Bogsnes ◽  
Mattias Hansson ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Cell Lines ◽  
Cell Separation ◽  
Line Length ◽  
Polymer Molecular Weight ◽  
Two Phase ◽  
Model Cell ◽  
Aqueous Two Phase Systems ◽  
Phase Systems ◽  
Tie Line

An Experimental Investigation on Thermal Conductivity and Viscosity of Graphene doped CNTs /TiO2 Nanofluid

2020 ◽  
Vol 17 (3) ◽  
Author(s):  
A.M. Zetty Akhtar ◽  
M.M. Rahman ◽  
K. Kadirgama ◽  
M.A. Maleque
Keyword(s):  
Thermal Conductivity ◽  
Zeta Potential ◽  
Base Fluid ◽  
Minimum Quantity Lubrication ◽  
Cutting Fluid ◽  
Cutting Zone ◽  
Observation Method ◽  
The Stability ◽  
The Relationship ◽  
Zeta Potential Analysis

This paper presents the findings of the stability, thermal conductivity and viscosity of CNTs (doped with 10 wt% graphene)- TiO2 hybrid nanofluids under various concentrations. While the usage of cutting fluid in machining operation is necessary for removing the heat generated at the cutting zone, the excessive use of it could lead to environmental and health issue to the operators. Therefore, the minimum quantity lubrication (MQL) to replace the conventional flooding was introduced. The MQL method minimises the usage of cutting fluid as a step to achieve a cleaner environment and sustainable machining. However, the low thermal conductivity of the base fluid in the MQL system caused the insufficient removal of heat generated in the cutting zone. Addition of nanoparticles to the base fluid was then introduced to enhance the performance of cutting fluids. The ethylene glycol used as the base fluid, titanium dioxide (TiO2) and carbon nanotubes (CNTs) nanoparticle mixed to produce nanofluids with concentrations of 0.02 to 0.1 wt.% with an interval of 0.02 wt%. The mixing ratio of TiO2: CNTs was 90:10 and ratio of SDBS (surfactant): CNTs was 10:1. The stability of nanofluid checked using observation method and zeta potential analysis. The thermal conductivity and viscosity of suspension were measured at a temperature range between 30˚C to 70˚C (with increment of 10˚C) to determine the relationship between concentration and temperature on nanofluid’s thermal physical properties. Based on the results obtained, zeta potential value for nanofluid range from -50 to -70 mV indicates a good stability of the suspension. Thermal conductivity of nanofluid increases as an increase of temperature and enhancement ratio is within the range of 1.51 to 4.53 compared to the base fluid. Meanwhile, the viscosity of nanofluid shows decrements with an increase of the temperature remarks significant advantage in pumping power. The developed nanofluid in this study found to be stable with enhanced thermal conductivity and decrease in viscosity, which at once make it possible to be use as nanolubricant in machining operation.

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