Bicontinuous Microemulsion as Reaction Medium for ω-Transaminase Catalysed Biotransformations

Due to their high enantioselectivity biotransformations, i.e. enzyme-catalysed conversion of organic compounds, are extremely attractive reactions. However, a limiting factor for choosing substrates is the enzyme-substrate incompatibility. This occurs when a hydrophilic enzyme which naturally resides in the aqueous cell cytoplasm is supposed to convert a hydrophobic substrate. In this context bicontinuous microemulsions appear to be a beneficial reaction medium for biotransformations, particularly due to their large interfacial area between a hydrophilic and a hydrophobic compound. As a "proof of concept" we performed omega-transaminase (EC 2.6.1.18) catalysed model reactions in a bicontinuous microemulsion of the type phosphate buffer/NaCl - n-octane - pentaethylene glycol monodecyl ether.