Integrated lipase-catalyzed isoamyl acetate synthesis in a miniaturized system with enzyme and ionic liquid recycle

• Published in: gps
• Main Authors: Novak, Uroš, Žnidaršič-Plazl, Polona
• Format: Article in Journal/Newspaper
• Language: English
• Published: Walter de Gruyter GmbH 2013
• Subjects: Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1515/gps-2013-0082; https://www.degruyter.com/document/doi/10.1515/gps-2013-0082/xml; https://www.degruyter.com/document/doi/10.1515/gps-2013-0082/pdf

Abstract Isoamyl acetate synthesis employing aqueous Candida antarctica lipase B (CaLB) solution was performed in a two-phase solvent system comprising hydrophilic ionic liquid 1-butyl-3-methylpyridinium dicyanamide and n -heptane. An X-junction glass microfluidic chip was used to obtain uniform microdroplets of n -heptane within a continuous phase of ionic liquid with dissolved enzyme and reactants, namely, isoamyl alcohol and acetic anhydride. A developed flow pattern resulted in a very large specific interfacial area for the reaction with amphiphilic CaLB and simultaneous extraction of isoamyl acetate in n -heptane. Biotransformation was performed within a continuously operated microfluidic system consisting of an X-junction chip and a silanized tube of a submillimeter diameter, which was further integrated with a microseparator based on a hydrophobic membrane. Efficient separation of n -heptane with product from ionic liquid phase containing enzyme and remaining substrates and products was achieved, enabling reuse of CaLB together with ionic liquid phase. More than 80% of productivity was preserved in each of the eight consecutive biotransformations within the integrated microfluidic system with reused lipase B in the ionic liquid phase. Subsequent ionic liquid regeneration accomplished by vacuum distillation enabled efficient reuse of this solvent in esterification with fresh enzyme.