Biocatalysis in neoteric solvents

alpha-Chymotrypsin was found to be a robust enzyme capable of retaining its structure and activity in a large variety of different solvent environments. The kinetics of the enzyme were found to be affected most strongly by the solvent viscosity, whereas the product distribution, structure, and permanent loss of activity over time were found to be affected mainly by the solvent polarity. A new class of 'ionic-liquid-like' solvents, the deep eutectics, were also investigated for their suitability as solvents for biocatalysis for the first time and found to be comparable to conventional ionic liquids.;The nature of deep eutectic solvents and their effect on enzyme structure and kinetics was further investigated using fifteen lipases from different sources and seven eutectic solvents with different properties. Kamlet-Taft solvatochromatic parameters were determined for the eutectic solvents. The solubility of the lipases was found to affect how strongly the solvent interacted with the enzyme structure using UV spectrophotometric techniques.;The biodiesel process was attempted using lipases as catalysts and eutectic solvents as a method of extracting the by product glycerol from the system. Although the lipases were found not to be as effective as the conventional base catalysts for the reaction, there were several advantages to using them. Eutectic solvents of glycerol did not form spontaneously upon addition to the salt to the crude biodiesel-glycerol mixture, but it was found that a sub-eutectic molar composition of glycerol: salt would extract glycerol to the eutectic point from the mixture.