ABSTRACT
This chapter discusses the advantages of using nonaqueous media in biochemical synthesis reactions, over aqueous and solvent-free systems. It focuses on the use of supercritical fluids as a green alternative reaction medium and describes ionic liquids as another alternative. The chapter explores these solvents and the factors affecting their physical properties and their effect on the activity and stability of lipase. From a technical-economical point of view, carrying out lipase-catalyzed reactions in solvent-free systems is the most effective strategy. Typically, the absence of water affects lipase conformation, as a small hydration layer is usually required for the interfacial activation of lipase. Reacting lipophilic substrates with hydrophilic compounds, as in the case of most transesterification reactions, is one of the major difficulties in lipase-catalyzed reactions. Supercritical ethane has been used successfully in enzymatic-catalyzed reactions; however, it has never been used with lipase.
