Ionic liquids have been successfully proposed to modify membrane permeability in cultures of a model extremophilic bacterium Thermus thermophilus HB27, which makes up the first time that aqueous solutions of these molten salts are applied in downstream stages of this kind of microorganisms. The presence of 1 g/L of C10MIMCl entails a great solubilisation of cell biomass, thus allowing the release of intracellular and membrane-bound enzyme. The influence on the enzyme activity of two inorganic salts such as Na2CO3 and (NH4)(2)SO4, selected on the basis of their high salting out potential and biocompatibility with enzymes, respectively, was investigated. In parallel, their ability to trigger phase segregation was confirmed in the presence of the enzyme crude, leading to very high levels of enzyme extraction (96%). The validity of the strategy was confirmed by operating at bioreactor scale, and the main bioprocess parameters were obtained by modelling the experimental data. (C) 2015 Elsevier Ltd. All rights reserved.