title: Response surface methodology to optimize partition and purification of two recombinant oxidoreductase enzymes, glucose dehydrogenase and d-galactose dehydrogenase in aqueous two-phase systems.
abstract: Oxidoreductases are an important family of enzymes that are used in many biotechnological processes. An experimental design was applied to optimize partition and purification of two recombinant oxidoreductases, glucose dehydrogenase (GDH) from Bacillus subtilis and d-galactose dehydrogenase (GalDH) from Pseudomonas fluorescens AK92 in aqueous two-phase systems (ATPS). Response surface methodology (RSM) with a central composite rotatable design (CCRD) was performed to optimize critical factors like polyethylene glycol (PEG) concentration, concentration of salt and pH value. The best partitioning conditions was achieved in an ATPS composed of 12% PEG-6000, 15% K2HPO4 with pH 7.5 at 25°C, which ensured partition coefficient (KE) of 66.6 and 45.7 for GDH and GalDH, respectively. Under these experimental conditions, the activity of GDH and GalDH was 569.5U/ml and 673.7U/ml, respectively. It was found that these enzymes preferentially partitioned into the top PEG-rich phase and appeared as single bands on SDS-PAGE gel. Meanwhile the validity of the response model was confirmed by a good agreement between predicted and experimental results. Collectively, according to the obtained data it can be inferred that the ATPS optimization using RSM approach can be applied for recovery and purification of any enzyme from oxidoreductase family.
authors.affiliation: Department of Biochemistry, Genetic and Metabolism Research Group, Pasteur Institute of Iran, Tehran 13164, Iran; Department of Marine Biology, Islamic Azad University, Bandar Abbas Branch, Bandar Abbas, Iran.
authors.forename: Hamid
authors.initials: H
authors.lastname: Shahbaz Mohammadi
authors.affiliation: Department of Marine Biology, Islamic Azad University, Bandar Abbas Branch, Bandar Abbas, Iran.
authors.forename: Seyede Samaneh
authors.initials: SS
authors.lastname: Mostafavi
authors.affiliation: Department of Marine Biology, Islamic Azad University, Bandar Abbas Branch, Bandar Abbas, Iran.
authors.forename: Saeideh
authors.initials: S
authors.lastname: Soleimani
authors.affiliation: Department of Marine Biology, Islamic Azad University, Bandar Abbas Branch, Bandar Abbas, Iran. Electronic address: sajad_bozorgian@yahoo.com.
authors.forename: Sajad
authors.initials: S
authors.lastname: Bozorgian
authors.affiliation: Department of Microbiology, Islamic Azad University, East Tehran Branch, Tehran, Iran. Electronic address: maryam_porasgari@yahoo.com.
authors.forename: Maryam
authors.initials: M
authors.lastname: Pooraskari
authors.affiliation: Department of Medical Biotechnology, School of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran. Electronic address: kiabiotpro@yahoo.com.
authors.forename: Anvarsadat
authors.initials: A
authors.lastname: Kianmehr
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D005691:Galactose Dehydrogenases / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D042843:Glucose 1-Dehydrogenase / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D011551:Pseudomonas fluorescens / Q000201:enzymology* / Q000235:genetics; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification
chemical_list: D001426:Bacterial Proteins; D011994:Recombinant Proteins; D005691:Galactose Dehydrogenases; D042843:Glucose 1-Dehydrogenase; C047959:galactose dehydrogenase
keywords: Aqueous two-phase systems (ATPS); Glucose dehydrogenase (GDH); Partition; Purification; Response surface methodology (RSM); d-Galactose dehydrogenase (GalDH)