Enzymes in neoteric solvents: From one-phase to multiphase systems

Biphasic systems based on neoteric solvents, e.g. ionic liquids (ILs), supercritical carbon dioxide (scCO(2)), fluorous solvents (FSs) and liquid polymers (LPs), represent interesting alternatives to organic solvents for designing continuous clean biotransformations methods in non-aqueous environments that directly provide pure products. The classical advantages of scCO(2) - its ability to extract, dissolve and transport chemicals are complemented by the high catalytic efficiency of enzymes in liquid neoteric solvents (e.g. ILs, LPs or FSs). Enzyme behaviour in scCO(2) and ILs, as well as the phase behaviour of ILs/scCO(2), are key parameters for carrying out integral green bioprocesses in continuous operation. Experimental approaches, reactor designs and results are discussed in this Critical review.