Aqueous two phase systems (ATPSs) containing high molecular weight polyethylene glycol, PEG (10000), and completely biodegradable citrate salts (sodium citrate, potassium citrate, and ammonium citrate) with water were developed to recover the waste water proteins from a model tannery waste water system. The variations in the phase diagram were explained on the basis of ionic radius of cations, Gibbs free energy of hydration ( ) of cations, and effective excluded volume (EEV) of salts. The salting-out capability of the cations followed the sequence: Sodium citrate > Potassium citrate > Ammonium citrate. Setschenow-type equations were used to correlate tie-line compositions. During partitioning studies, recovery of tannery waste water proteins in PEG 10000 + Sodium citrate ATPS was found superior to other systems. It was possible to recover 95.86% of proteins from tannery waste water in the bottom phase with PEG 10000 30% (w/w) + Sodium citrate 13% (w/w) at 30°C. The partition coefficients were correlated with the salt compositions by a quadratic equation and the coefficients were calculated. 1. Introduction Leather industry is one of the prominent industries in Indian economy which potentially provides employment, growth, and export. Up to date, approximately 2000 tanneries are present in India [1] and the waste water generated from them is enormous. During leather processing the skin and hides have to undergo series of processes such as soaking, liming, dehairing, bating, and degreasing. When the skin is subjected to liming process, the collagen structure will be swollen and the fiber bundles are opened up. This step enables the removal of interfibrillary soluble proteins and other biomolecules [2]. The presence of these proteins in the tannery waste water (TWW) effluents increases the biological oxygen demand and chemical oxygen demand and leads to pollution. Currently research is focused on the recovery of valuables from waste effluent generated by the industries. Instead of merely letting off these effluents, the biomolecules present in them can be recovered, since these biomolecules find applications in food and pharmaceutical industries [3]. Thus in this context, a separation method, aqueous two phase system (ATPS) is employed to recover the soluble proteins present in the TWW. ATPS is based on liquid-liquid extraction principle and can be formulated by mixing two chemically differing hydrophilic polymers or one hydrophilic polymer and one salt with water above certain concentrations [4]. It has been proved that a salt-based ATPS is an efficient
References
[1]
S. Sanyal, S. Banerjee, and S. Majumder, “India’s leather in the world market: exploration of recent trends,” Trade and Development Review, vol. 3, pp. 22–58, 2010.
[2]
R. B. Choudhary, A. K. Jana, and M. K. Jha, “Enzyme technology applications in leather processing,” Indian Journal of Chemical Technology, vol. 11, no. 5, pp. 659–671, 2004.
[3]
J. Benavides and M. Rito-Palomares, “Practical experiences from the development of aqueous two-phase processes for the recovery of high value biological products,” Journal of Chemical Technology and Biotechnology, vol. 83, no. 2, pp. 133–142, 2008.
[4]
R. Hatti-Kaul, Aqueous Two Phase Systems: Methods and Protocols, Humana Press, Totowa, NJ, USA, 2000.
[5]
A. B. Mageste, L. R. de Lemos, G. M. D. Ferreira et al., “Aqueous two-phase systems: an efficient, environmentally safe and economically viable method for purification of natural dye carmine,” Journal of Chromatography A, vol. 1216, no. 45, pp. 7623–7629, 2009.
[6]
H. Cabezas, “Theory of phase formation in aqueous two-phase systems,” Journal of Chromatography B, vol. 680, no. 1-2, pp. 3–30, 1996.
[7]
F. Rahimpour, F. Feyzi, S. Maghsoudi, and R. Hatti-Kaul, “Purification of plasmid DNA with polymer-salt aqueous two-phase system: optimization using response surface methodology,” Biotechnology and Bioengineering, vol. 95, no. 4, pp. 627–637, 2006.
[8]
J. C. Marcos, L. P. Fonseca, M. T. Ramalho, and J. M. S. Cabral, “Application of surface response analysis to the optimization of penicillin acylase purification in aqueous two-phase systems,” Enzyme and Microbial Technology, vol. 31, no. 7, pp. 1006–1014, 2002.
[9]
G. Pazuki, M. Vossoughi, and V. Taghikhani, “Partitioning of penicillin G acylase in aqueous two-phase systems of poly(ethylene glycol) 20000 or 35000 and potassium dihydrogen phosphate or sodium citrate,” Journal of Chemical and Engineering Data, vol. 55, no. 1, pp. 243–248, 2010.
[10]
G. G. G. Oliveira, D. P. Silva, I. C. Roberto, M. Vitolo, and A. Pessoa, “Partition behavior and partial purification of hexokinase in aqueous two-phase polyethylene glycol/citrate systems,” Applied Biochemistry and Biotechnology A, vol. 108, no. 1–3, pp. 787–798, 2003.
[11]
W. Zhi, J. Song, J. Bi, and F. Ouyang, “Partial purification of α-amylase from culture supernatant of Bacillus subtilis in aqueous two-phase systems,” Bioprocess and Biosystems Engineering, vol. 27, no. 1, pp. 3–7, 2004.
[12]
W. Zhi, J. Song, F. Ouyang, and J. Bi, “Application of response surface methodology to the modeling of α-amylase purification by aqueous two-phase systems,” Journal of Biotechnology, vol. 118, no. 2, pp. 157–165, 2005.
[13]
G. Tubío, B. Nerli, and G. Picó, “Partitioning features of bovine trypsin and α-chymotrypsin in polyethyleneglycol-sodium citrate aqueous two-phase systems,” Journal of Chromatography B, vol. 852, no. 1-2, pp. 244–249, 2007.
[14]
T. S. Porto, P. A. Pess？a-Filho, B. B. Neto et al., “Removal of proteases from Clostridium perfringens fermented broth by aqueous two-phase systems (PEG/citrate),” Journal of Industrial Microbiology and Biotechnology, vol. 34, no. 8, pp. 547–552, 2007.
[15]
T. S. Porto, G. M. Medeiros e Silva, C. S. Porto et al., “Liquid-liquid extraction of proteases from fermented broth by PEG/citrate aqueous two-phase system,” Chemical Engineering and Processing, vol. 47, no. 4, pp. 716–721, 2008.
[16]
A. M. Azevedo, A. G. Gomes, P. A. J. Rosa, I. F. Ferreira, A. M. M. O. Pisco, and M. R. Aires-Barros, “Partitioning of human antibodies in polyethylene glycol-sodium citrate aqueous two-phase systems,” Separation and Purification Technology, vol. 65, no. 1, pp. 14–21, 2009.
[17]
C. A. S. da Silva, J. S. R. Coimbra, E. E. G. Rojas, and J. A. C. Teixeira, “Partitioning of glycomacropeptide in aqueous two-phase systems,” Process Biochemistry, vol. 44, no. 11, pp. 1213–1216, 2009.
[18]
G. A. Gomes, A. M. Azevedo, M. R. Aires-Barros, and D. M. F. Prazeres, “Purification of plasmid DNA with aqueous two phase systems of PEG 600 and sodium citrate/ammonium sulfate,” Separation and Purification Technology, vol. 65, no. 1, pp. 22–30, 2009.
[19]
R. F. F. de Araújo, T. S. Porto, D. B. G. Martins, R. F. Dutra, A. L. F. Porto, and J. L. D. L. Filho, “Partitioning of lactate dehydrogenase from bovine heart crude extract by polyethylene glycol-citrate aqueous two-phase systems,” Fluid Phase Equilibria, vol. 301, no. 1, pp. 46–50, 2011.
[20]
C. S. Porto, T. S. Porto, K. S. Nascimento et al., “Partition of lectin from Canavalia grandiflora Benth in aqueous two-phase systems using factorial design,” Biochemical Engineering Journal, vol. 53, no. 2, pp. 165–171, 2011.
[21]
X. Li, Z. Lian, B. Dong, Y. Xu, Q. Yong, and S. Yu, “Extractive bioconversion of xylan for production of xylobiose and xylotriose using a PEG6000/sodium citrate aqueous two-phase system,” Korean Journal of Chemical Engineering, vol. 28, pp. 1897–1901, 2011.
[22]
D. Z. Ivetic, M. B. Sciban, V. M. Vasic, D. V. Kukic, J. M. Prodanovic, and M. G. Antov, “Evaluation of possibility of textile dye removal from wastewater by aqueous two-phase extraction,” Desalination and Water Treatment. In press.
[23]
S. Saravanan, J. R. Rao, T. Murugesan, B. U. Nair, and T. Ramasami, “Recovery of value-added globular proteins from tannery wastewaters using PEG-salt aqueous two-phase systems,” Journal of Chemical Technology and Biotechnology, vol. 81, no. 11, pp. 1814–1819, 2006.
[24]
R. Iyyaswami, P. D. Belur, B. Girish, and V. H. Nagaraj, “Development and evaluation of PEG-lithium citrate salt based aqueous two phase system and its application in partitioning of proteins from fish industry effluent,” Separation Science and Technology, vol. 47, pp. 591–598, 2012.
[25]
M. Perumalsamy and T. Murugesan, “Extraction of Cheese whey proteins (α-lactalbumin and β- lactoglobulin) from dairy effluents using environmentally benign aqueous biphasic system,” International Journal of Chemical and Environmental Engineering, vol. 3, pp. 55–59, 2012.
[26]
D. Ramyadevi, A. Subathira, and S. Saravanan, “Central composite design application for optimization of aqueous two-phase extraction of protein from shrimp waste,” Journal of Chemical and Pharmaceutical Research, vol. 4, pp. 2087–2095, 2012.
[27]
M. M. Bradford, “A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein dye binding,” Analytical Biochemistry, vol. 72, no. 1-2, pp. 248–254, 1976.
[28]
M. T. Zafarani-Moattar and A. A. Hamidi, “Liquid-liquid equilibria of aqueous two-phase poly(ethylene glycol)-potassium citrate system,” Journal of Chemical and Engineering Data, vol. 48, no. 2, pp. 262–265, 2003.
[29]
T. Murugesan and M. Perumalsamy, “Liquid-liquid equilibria of poly(ethylene glycol) 2000 + sodium citrate + water at (25, 30, 35, 40, and 45)°C,” Journal of Chemical and Engineering Data, vol. 50, no. 4, pp. 1392–1395, 2005.
[30]
G. Tubío, L. Pellegrini, B. B. Nerli, and G. A. Picó, “Liquid-liquid equilibria of aqueous two-phase systems containing poly(ethylene glycols) of different molecular weight and sodium citrate,” Journal of Chemical and Engineering Data, vol. 51, no. 1, pp. 209–212, 2006.
[31]
S. Saravanan, J. A. Reena, J. R. Rao, T. Murugesan, and B. U. Nair, “Phase equilibrium compositions, densities, and viscosities of aqueous two-phase poly(ethylene glycol) + poly(acrylic acid) system at various temperatures,” Journal of Chemical and Engineering Data, vol. 51, no. 4, pp. 1246–1249, 2006.
R. A. Curtis and L. Lue, “A molecular approach to bioseparations: protein-protein and protein-salt interactions,” Chemical Engineering Science, vol. 61, no. 3, pp. 907–923, 2006.
[35]
Y. Pei, J. Wang, L. Liu, K. Wu, and Y. Zhao, “Liquid-liquid equilibria of aqueous biphasic systems containing selected imidazolium ionic liquids and salts,” Journal of Chemical and Engineering Data, vol. 52, no. 5, pp. 2026–2031, 2007.
[36]
M. T. Zafarani-Moattar and S. Hamzehzadeh, “Liquid-liquid equilibria of aqueous two-phase systems containing 1-butyl-3-methylimidazolium bromide and potassium phosphate or dipotassium hydrogen phosphate at 298.15？K,” Journal of Chemical and Engineering Data, vol. 52, no. 5, pp. 1686–1692, 2007.
[37]
Y. Marcus, “Thermodynamics of solvation of ions. Part 5.—gibbs free energy of hydration at 298.15？K,” Journal of the Chemical Society, Faraday Transactions, vol. 87, no. 18, pp. 2995–2999, 1991.
[38]
Y. Marcus and A. Rashin, “A simple empirical model describing the thermodynamics of hydration of ions of widely varying charges, sizes, and shapes,” Biophysical Chemistry, vol. 51, no. 2-3, pp. 111–127, 1994.
[39]
Y. Wang, J. Wang, J. Han, S. Hu, and Y. Yan, “Liquid-liquid equilibrium of novel aqueous two-phase systems and evaluation of salting-out abilities of salts,” Central European Journal of Chemistry, vol. 8, no. 4, pp. 886–891, 2010.
[40]
Y. Guan, T. H. Lilley, and T. E. Treffry, “A new excluded volume theory and its application to the coexistence curves of aqueous polymer two-phase systems,” Macromolecules, vol. 26, no. 15, pp. 3971–3979, 1993.
[41]
R. Duraiayya, S. Arumugam, and S. Settu, “Equilibrium phase behavior of poly(ethylene glycol) 4000 and biodegradable salts at various temperatures [(20, 30, and 40)°C],” Journal of Chemical Engineering and Data, vol. 57, pp. 1112–1117, 2012.
[42]
M. J. Hey, D. P. Jackson, and H. Yan, “The salting-out effect and phase separation in aqueous solutions of electrolytes and poly(ethylene glycol),” Polymer, vol. 46, no. 8, pp. 2567–2572, 2005.
[43]
M. Perumalsamy and M. I. Batcha, “Synergistic extraction of bovine serum albumin using polyethylene glycol based aqueous biphasic system,” Process Biochemistry, vol. 46, no. 2, pp. 494–497, 2011.
[44]
K. Naganagouda and V. H. Mulimani, “Aqueous two-phase extraction (ATPE): an attractive and economically viable technology for downstream processing of Aspergillus oryzaeα-galactosidase,” Process Biochemistry, vol. 43, no. 11, pp. 1293–1299, 2008.
[45]
L. P. Malpiedi, G. Picó, and B. Nerli, “Features of partitioning pattern of two pancreatic enzymatic precursors: trypsinogen and chymotrypsinogen in polyethyleneglycol-sodium citrate aqueous biphasic systems,” Journal of Chromatography B, vol. 870, no. 1, pp. 1–7, 2008.
[46]
J. H. Han and C. H. Lee, “Effects of salts and poly(ethylene glycol)-palmitate on the partitioning of proteins and Bacillus subtilis neutral protease in aqueous two-phase systems,” Colloids and Surfaces B, vol. 9, no. 1-2, pp. 109–116, 1997.
[47]
I. S. Barberino do Nascimento, J. Sélia dos Reis Coimbra, J. P. Martins et al., “Partitioning of glutenin flour of special wheat using aqueous two-phase systems,” Journal of Cereal Science, vol. 52, no. 2, pp. 270–274, 2010.
[48]
R. C. F. Bonomo, L. A. Minim, J. S. R. Coimbra, R. C. I. Fontan, L. H. Mendes da Silva, and V. P. R. Minim, “Hydrophobic interaction adsorption of whey proteins: effect of temperature and salt concentration and thermodynamic analysis,” Journal of Chromatography B, vol. 844, no. 1, pp. 6–14, 2006.
[49]
A. D. Diamond and J. T. Hsu, “Correlation of protein partitioning in aqueous polymer two-phase systems,” Journal of Chromatography, vol. 513, pp. 137–143, 1990.
[50]
Z. Ziqiang, L. Mian, M. Lehe, and H. Zhaoxiong, “Measurement and correlation of partition coefficients of Urokinase in aqueous two-phase peg-potassium phosphate system,” Chinese Journal of Chemical Engineering, vol. 4, no. 1, pp. 19–27, 1996.
[51]
G. Blázquez, F. Camacho, P. González-Tello, and F. J. Alarcón, “Partition coefficients of α-amylase in aqueous two-phase systems PEG + MgSO4·7H2O + H2O at 298？K,” Biochimica et Biophysica Acta, vol. 1379, no. 2, pp. 191–197, 1998.
[52]
C. A. S. da Silva, J. S. R. Coimbra, E. E. G. Rojas, L. A. Minim, and L. H. M. da Silva, “Partitioning of caseinomacropeptide in aqueous two-phase systems,” Journal of Chromatography B, vol. 858, no. 1-2, pp. 205–210, 2007.
