Application of response surface methodology to the modeling of α-amylase purification by aqueous two-phase systems

• Published in: Journal of biotechnology 2005-08, Vol.118 (2), p.157-165
• Main Authors: Zhi, Wenbo, Song, Jiangnan, Ouyang, Fan, Bi, Jingxiu
• Format: Article
• Language: English
• Subjects: alpha-Amylases - chemistry; alpha-Amylases - isolation & purification; Aqueous two-phase systems; Bacillus subtilis; Bacillus subtilis - enzymology; Bacterial Proteins - chemistry; Bacterial Proteins - isolation & purification; Biological and medical sciences; Biotechnology; Citrates - chemistry; Fundamental and applied biological sciences. Psychology; Polyethylene Glycols - chemistry; Purification; Response surface methodology; α-Amylase
• ISSN: 0168-1656; 1873-4863
• DOI: 10.1016/j.jbiotec.2005.03.017

Mathematical models concerning the purification of α-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 α-amylase, total protein, purification factor and α-amylase yield. An experimental space with two-fold purification and over 90% yield of α-amylase is achieved through the optimized condition basing on the model. Two systems with low viscosity within said space were further selected to perform α-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.