A liquid immobilisation concept for enzymes by thermomorphic solvent systems

Biotechnology is playing an ever increasing role in industrial supply chains, however, only a few processes exist in which the expensive native enzyme can be economically separated and re-used with little or no loss of activity. In this report, a new and innovative recycling method for free enzymes is presented which is based solely on the temperature-dependent miscibility gap of the selected solvent mixture. The reaction is carried out under monophasic conditions with no mass transfer limitations. Cooling down leads to a biphasic system in which the catalyst phase containing the enzyme can be simply separated from the product phase and used again. The performance of this new recycling method was proven by the lipase-catalysed hydrolysis of p-nitrophenyl palmitate. Only a 2% loss in maximum yield was observed over five sequential recycling runs.