Added value of ionic liquids in a biocatalytic process: An automatic approach

Abstract Understanding the potential of ionic liquids in biocatalysis is both useful and difficult. The unique properties of ionic liquids, such as their tunability, allow for the medium to be adjusted to the reaction, thereby supporting both substrate solubility and enzyme activity. Thus, the effect of 9 different ionic liquids with different structures (in terms of cation, anion, and the attached substituents) on the activity of β-galactosidase, an enzyme widely used in food industry processes, was investigated. According to the findings of this study, three of the nine tested ionic liquids promoted an increase in β-galactosidase activity, while two of them ([bmpyr][Cl] and [bmpyr][BF4]) promoted an inactivation (with EC50 of 20.4 and 10.7 mmol L−1, respectively), most likely due to the presence of the cation [bmpyr]. Some correlations between the structure of ionic liquids and the activity of β-galactosidase were established. To carry out these studies, a microfluidic automatic system was used, allowing for greater control of the reaction conditions as well as a reduction in reagent consumption and waste generation. It demonstrated the system's potential as a simple, versatile, robust, and fast analytical tool for the automation of enzymatic assays in ILs medium.