Compressed gases as alternative enzymatic-reaction solvents: a short review

Application of supercritical fluids and liquid gases as an alternative reaction medium for enzyme-catalysed reactions is presented. The factors affecting the enzyme stability in supercritical fluids (effect of water activity, effect of pressure and temperature, number of pressurisation–depressurisation steps) and inhibition of enzymes are well documented with experimental results on hydrolases. An overview of our research on various types of HP enzymatic batch-stirred-tank-, continuous-packed-bed- and continuous-membrane reactors to obtain data on productivity and to evaluate the economy of the process is given.