Deep eutectic solvents based on choline cation - Physicochemical properties and influence on enzymatic reaction with β-galactosidase.

In presented study analysis of physicochemical properties of deep eutectic solvents (DESs) and their usefulness as an element of reaction medium for β-galactosidase from Kluyveromyces lactis was conducted. Analyzed DESs were based on choline salt derivatives: choline chloride, choline acetate and hydrogen bond-donors (HBD) such as: glycerol, ethylene glycol, urea, thiourea and levulinic acid. Results showed that reaction medium with appropriate amount of DES based on choline acetate had beneficial effect on activity of β-galactosidase. The 5% (v/v) addition of developed choline acetate:glycerol DES mixture enhanced enzyme activity almost three fold. The results of performed experiments have also revealed that β-galactosidase activity is less affected by the organic anion as choline acetate in ionic liquid, than inorganic anion as choline chloride. The developed green solvents as DES based on choline acetate exhibit a wide application potential that can be used to increase efficiency of enzyme-based industrial process.