Partial purification of alpha-amylase from culture supernatant of Bacillus subtilis in aqueous two-phase systems.
A study was made of the partition and purification of alpha-amylase from a culture supernatant of Bacillus subtilis in the polyethylene glycol (PEG)--citrate aqueous two-phase system (ATPS). Factors that influenced the partition of the protein in this system, including the molecular weight of the PEG, the tie line length of ATPS, the pH value and the sodium chloride concentration, were investigated. Purification of alpha-amylase was attained with a purification factor (PF) of 1.8 and 90% yield at pH 6.0 in a PEG1000-citrate ATPS with short tie line length. By utilizing the salt-out effect of neutral salt, the purification of alpha-amylase was further improved to 2.0 of PF and 80% yield in a PEG3350-citrate ATPS with 4% sodium chloride.
National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100080, People's Republic of China. zhiwenbo@sohu.com
Wenbo
W
Zhi
Jiangnan
J
Song
Jingxiu
J
Bi
Fan
F
Ouyang
D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics; D018929:Cell Culture Techniques / Q000379:methods*; D005591:Chemical Fractionation / Q000379:methods*; D003470:Culture Media / Q000737:chemistry / Q000302:isolation & purification; D004789:Enzyme Activation; D006863:Hydrogen-Ion Concentration; D011092:Polyethylene Glycols / Q000737:chemistry*; D015202:Protein Engineering / Q000379:methods; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification; D012965:Sodium Chloride / Q000737:chemistry*; D000516:alpha-Amylases / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification*
D003470:Culture Media; D011994:Recombinant Proteins; D011092:Polyethylene Glycols; D012965:Sodium Chloride; D000516:alpha-Amylases