ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Preparation and properties of surfactant-bacillolysin ion-pair in organic solvents

Ying Zhang, Jiadong Gu, Shugen Wang, and Xuerong Fan

Key Laboratory of Eco-Textiles, School of Textiles and Clothing, Jiangnan University, Wuxi, 214122, China

E-mail: yingzhang@jiangnan.edu.cn

Received: 29 June 2009  Revised: 5 November 2009  Accepted: 1 December 2009

Abstract: The transesterification-active enzyme bacillolysin was extracted into organic solvents such as isooctane by enzyme-AOT (bis (2-ethylhexyl) sulfosuccinate) ion-pairing preserving its natural second structure and catalytic activity. Extraction efficiency was affected by the interaction mode of the two phases, ionic strength, and pH of aqueous phase, surfactant and enzyme concentration. Magnetic stirring with phase mixing was favorable for the enzyme extraction. Optimal ionic strength and pH were 8 mM CaCl₂ and 5.0, respectively. Critical number of AOT molecule for an enzyme molecule to be extracted into isooctane was 89. Optimal initial enzyme concentration in the aqueous phase was 7 mg mL⁻¹ while the initial AOT concentration in isooctane was 3 mM. Within CMC (critical micellar concentration) of AOT in isooctane, the increase of initial AOT concentration enhanced the extraction efficiency.

Keywords: bacillolysin - AOT - ion-pair - solvent - transesterification

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-010-0018-6

Chemical Papers 64 (4) 443–449 (2010)