Choline dihydrogen phosphate-based deep eutectic solvent: A suitable bioplatform for lipase extraction

• ChDHP -based DES promotes segregation in aqueous solutions of non-ionic surfactants. • Empirical equations adequately model the experimental equilibrium data. • Candida antarctica lipase B can be efficiently separated in ChDHP-rich phase. • ChDHP-based DES did not entail any deleterious effect on lipolytic activity. In this work, we have demonstrated the suitability of a novel Deep Eutectic Solvent (DES) composed of cholinium dihydrogen phosphate and ethylene glycol at a molar ratio of 1:2 (ChDHP:EG) to extract Candida antarctica lipase B from aqueous solutions of non-ionic surfactants Triton X-100 and Tween 80. The binodal curves were firstly explored at temperatures between 298.15 and 333.15 K and the experimental data were correlated by means of empirical models based on exponential and polynomial equations. The tie-lines have been ascertained by means of density and refractive indices measurement, and Othmer-Tobias, Bancroft and Setschenow equations were proposed to correlate these data. The Tween 80-based Aqueous Biphasic System was demonstrated to avoid any deleterious effect on the lipase biocatalytic activity, and more than 80% of the enzyme activity was retained on the DES-rich phase, which proves the suitability of these platforms to be employed in downstream stages in lipase production processes.