Abstract

DES have been studied for biocatalysis with hydrolases, oxidoreductases, laccases, lyases, etc., using free enzymes or whole-cells. DES can be used as solvents for biotransformations, enabling the dissolution of substrates with different polarities, opening options for challenging reactions. The addition of water as cosolvent up to 20% (v/v) leads to DES-water mixtures with diminished viscosity but remaining as non-aqueous solvent. For enzyme-catalysis DES can also be used as co-solvents, when water is added in larger amounts (>20% v/v). In these cases, improvements in enzyme stability and selectivity have been described. Finally, DES can be used as media for multi-step catalytic processes, as well as for end-of-pipe tools to separate products and substrates efficiently, after an enzymatic transformation. Overall, DES represent solid, sustainable, and promising alternatives for biocatalysis.