title: Application of response surface methodology to the modeling of alpha-amylase purification by aqueous two-phase systems.
abstract: Mathematical models concerning the purification of alpha-amylase from the cultivation supernatant of Bacillus subtilis in a polyethylene glycol-citrate aqueous two-phase system (ATP) are established with response surface methodology. The PEG3350, citrate and sodium chloride concentrations were selected as variables to evaluate the purification impact factors in aqueous two-phase system, including partition coefficients of alpha-amylase, total protein, purification factor and alpha-amylase yield. An experimental space with two-fold purification and over 90% yield of alpha-amylase is achieved through the optimized condition basing on the model. Two systems with low viscosity within said space were further selected to perform alpha-amylase purification and the experimental results coincide well with the calculation of the models, which indicates that the model provides a promising tool for experimental design of protein purification by aqueous two-phase system.
authors.affiliation: National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100080, PR China.
authors.forename: Wenbo
authors.initials: W
authors.lastname: Zhi
authors.forename: Jiangnan
authors.initials: J
authors.lastname: Song
authors.forename: Fan
authors.initials: F
authors.lastname: Ouyang
authors.forename: Jingxiu
authors.initials: J
authors.lastname: Bi
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification*; D002951:Citrates / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D000516:alpha-Amylases / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D001426:Bacterial Proteins; D002951:Citrates; D011092:Polyethylene Glycols; D000516:alpha-Amylases