Partitioning of α-amylase in aqueous biphasic system based on hydrophobic and polar ionic liquid: Enzyme extraction, stripping, and purification

ABSTRACT

Controlled partitioning of a commercial α-amylase is achieved in aqueous biphasic system (ABS) of a hydrophobic and polar ionic liquid, 3-methyl-1-octylimidazol-3-ium saccharinate ([C₈C₁im][Sac]). Studying the effects of pH and [C₈C₁im][Sac]-concentration, the IL interference in the amylolytic action is deduced. Liquid–liquid extractions into [C₈C₁im][Sac] at different pHs are carried out. The α-amylase extraction occurs below pH = pI (isoelectric point), and above pI other inactive proteins are preferably transferred. The extracted α-amylase is afterwards recovered, being partially purified from inactive protein and microbial pigment. In the ABSs of pHs > pI, the α-amylase remains concentrated and purified in the aqueous raffinates.

KEYWORDS:

• α-Amylase
• ionic liquid
• liquid–liquid extraction
• imidazolium saccharinate
• purification

Funding

A grant of the Bulgarian Science Fund, Bulgarian Ministry of Education and Science (contract grant number DFNI T02/23) is gratefully acknowledged.

Additional information

Funding

A grant of the Bulgarian Science Fund, Bulgarian Ministry of Education and Science (contract grant number DFNI T02/23) is gratefully acknowledged.