Exploring the behavior of Candida antarctica lipase B in aqueous mixtures of an imidazolium ionic liquid and its surfactant analogue

The performance of Candida antarctica lipase B (CALB) has been evaluated in 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4)/water mixtures in a wide range of molar fractions (chi(BMIMBF4)) with and without 1-dodecyl-3-methylimidazolium tetrafluoroborate (C12-MIMBF4), a surfactant derived from BMIMBF4. The main aim of this work is to evaluate the influence of chi(BMIMBF4) over micellar aggregates to assess the activity of enzymatic reactions. The investigated reaction corresponds to the hydrolysis of the substrate p-nitrophenyl laureate in each chi(BMIMBF4). The kinetic study for chi(BMIMBF4) at around 0.2 proved to be a border point in enzymatic activity. At chi(BMIMBF4) = 0.1, the lipase activity increases in the presence of C-12-MIMBF4. However, at higher concentrations, BMIMBF(4 )has a negligible effect over the lipase activity. These results suggest specific interactions between water and BMIMBF(4 )molecules in relation to CALB. This research highlights the superactivity phenomenon driven by the reaction media and the micelle interface. In this interfacial interaction, BMIMBF4 acts directly on the changes induced on the enzyme upon its interaction with the micellar interface. This study opens a green perspective toward the biocatalysis field.