Biphasic mini‐reactor for characterization of biocatalyst performance

Abstract

Biphasic reaction media are extending the scope of technical biocatalysis. Thorough investigation of the factors affecting catalyst performance under these conditions is of key importance for the successful implementation of catalytic processes. Here, we present a reactor setup suitable for comprehensive systematic characterization and optimization of biocatalyzed reactions in biphasic systems with distinct phases. It is distinguished by small volumes allowing reproducible experimentation with minimum amounts of solvent and catalyst. The interfacial area is kept constant and independent stirring of both phases is allowed in order to minimize superimposing effects. Evaporation of low‐volatile organic solvents is prevented by use of airtight construction. The broad applicability of this mini‐reactor is demonstrated with regard to determination of mass transfer, enzyme productivity, and enzyme stability in both batch and continuous mode.

Efficient Chemo‐Enzymatic Epoxidation Using silcoat‐Novozym®435: Characterizing the Multiphase System

“…All other experiments were carried out in a double-walled glass vessel (10 mL reaction volume) that was constructed at the university workshop of RWTH Aachen (Germany) [14]. All other experiments were carried out in a double-walled glass vessel (10 mL reaction volume) that was constructed at the university workshop of RWTH Aachen (Germany) [14].…”

“…For initial small-scale experiments, 1.5 mL standard GC glass screw-cap vials (Agilent Technologies, USA) were placed on a vibrating platform shaker (Vibramax 110, Heidolph Instruments, Kelheim, Germany). All other experiments were carried out in a double-walled glass vessel (10 mL reaction volume) that was constructed at the university workshop of RWTH Aachen (Germany) [14]. With an internal diameter of 20 mm and liquid height of 32 mm, the test cell provides a cross-sectional area of 3.1 cm 2 (which also is the specific interfacial area in the absence of dispersion).…”

Activity of Lactobacillus brevis Alcohol Dehydrogenase on Primary and Secondary Alcohol Biofuel Precursors

“…[7]. Several studies, meanwhile, have studied the ability of LbADH to catalyze the stereoselective reduction of 2-butanone [8][9][10]. Erdmann et al, for example, recently demonstrated that whole cells of recombinant Escherichia coli expressing LbADH could be employed in a novel continuous reactor process to convert 2-butanone to (R)-2-butanol at >99% conversion and >96% e.e., while also achieving space time yields of ~2300 g/L-d [8].…”

Thermodynamic activity‐based intrinsic enzyme kinetic sheds light on enzyme–solvent interactions

“…MTBE is often used for biphasic biocatalytic reactions using LbADH because of its favorably increased equilibrium conversion, yield, and enzyme stability. 7,[34][35][36] In biphasic systems, enzymes are dissolved in the MTBEsaturated buffer phase. Thus, an enhanced LbADH stability in a biphasic system should also apply in a monophasic system because of the avoidance of an additional liquid/liquid interface and of potential enzyme inactivation.…”