Ionic Liquids and their Toxicity on the Enzyme Activity and Stability

Molecular interactions are crucial between the enzyme molecules and the surrounding solution in an enzymatic catalysis. Although aqueous solutions used as conventional enzymatic reaction media, non-aqueous enzymology emerges as a major area of biotechnology research and development. Ionic liquids, as new generation of promising alternatives to traditional organic solvents, possess potential industrial enzymatic applications. Enzymes in ionic liquids present enhanced activity, stability, and selectivity. In addition, the potential of ionic liquids in bio-catalysis is raised by high ability of dissolving a wide variety of substrates and their extensively tunable solvent properties through appropriate modification of the cations and anions. However, despite the bio-friendly nature of ionic liquids for enzymatic reactions, their growing interests increase concerns associated with toxicity and environmental pollution of such compounds. This mini-review presents a brief highlight of the contemporary knowledge of enzymes activity and stability in ionic liquids and the environmental influences regarding the potential risks related to the growing applications of these green solvents.HIGHLIGHTS•Conventional organic solvents can be replaced by ionic liquids as green solvents.•Ionic liquids are used as additives, catalysts, or reaction media in industries.•Advantages and disadvantages of ionic liquids are discussed.•Potential environmental hazards linked to application of ionic liquids are highlighted.•The environmental fate needs to be considered in designing safer ionic liquids