title: Optimization of pancreatic trypsin extraction in PEG/citrate aqueous two-phase systems.
abstract: Enzyme extraction using aqueous two-phase systems (ATPS) has been increasingly used as a primary recovery technique which integrates the clarification, concentration and partial purification of important biomolecules from their natural source in a single step. The goal of this work was to optimize the extraction of trypsin from pancreas homogenate with polyethylene glycol and sodium citrate (PEG/NaCit) ATPS by using the tools of experimental design. The variables NaCl concentration - added inert salt -, the top/bottom phase volume ratio - Vr - and the biomass loaded into the system - in percentage - were selected as the main factors in the trypsin extraction. The yield (%) and the purification factor of trypsin were considered the responses to be optimized. The central composite design and the response surface analysis proved to be suitable tools for a quick and efficient study. As a result, the optimal extraction conditions in PEG3350/NaCit system were 3.34% wt/wt for NaCl concentration, a biomass load which represented 9.30% wt/wt of the total ATPS mass and 6.37 top/bottom volume ratio giving a purification factor of 2.55 and a yield of 99.7% in top phase.
authors.affiliation: Departamento de Químico-Física, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Argentina.
authors.forename: Rocío L
authors.initials: RL
authors.lastname: Pérez
authors.affiliation: Departamento de Químico-Física, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Argentina.
authors.forename: Dana B
authors.initials: DB
authors.lastname: Loureiro
authors.affiliation: Departamento de Química-Física, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Instituto de Procesos Biotecnológicos y Químicos (IPROBYQ), CONICET, Argentina.
authors.forename: Bibiana B
authors.initials: BB
authors.lastname: Nerli
authors.affiliation: Departamento de Química-Física, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Instituto de Procesos Biotecnológicos y Químicos (IPROBYQ), CONICET, Argentina. Electronic address: gtubio@conicet.gov.ar.
authors.forename: Gisela
authors.initials: G
authors.lastname: Tubio
mesh_terms: D000818:Animals; D001671:Biochemistry / Q000379:methods*; D002417:Cattle; D002951:Citrates / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D010179:Pancreas / Q000201:enzymology*; D010184:Pancreatic Extracts / Q000378:metabolism; D011092:Polyethylene Glycols / Q000737:chemistry*; D012044:Regression Analysis; D015203:Reproducibility of Results; D000077559:Sodium Citrate; D014357:Trypsin / Q000302:isolation & purification*; D014867:Water
chemical_list: D002951:Citrates; D010184:Pancreatic Extracts; D014867:Water; D000077559:Sodium Citrate; D011092:Polyethylene Glycols; D014357:Trypsin
keywords: Aqueous two-phase systems; Extraction; Pancreatic trypsin; Statistic optimization