Production of pyruvate from (R)-lactate in an enzyme-membrane reactor with coupled electrochemical regeneration of the artificial mediator anthraquinone-2,6-disulfonate

The production of pyruvate from (R)-lactate using the enzyme (2R)-hydroxycarboxylate-violagen-oxidoreductase in the form of a elude extract of Protons vulgaris cells was studied in art enzyme-membrane reactor with coupled electrochemical regeneration of the mediator. The artificial mediator anthraquinone-2,6-disulfonate served as the electron acceptor. A cross-flow membrane module was used for enzyme retention. The kinetics of the electrochemical cell and the enzymatic reaction rates were measured and used for simple mechanistic modeling Model calculations agreed well with the experimental data. The overall reactor performance was limited by membrane fouling; however with optimized operating conditions, enzyme deactivation was practically eliminated. A high enzyme activity could be maintained in the enzyme-membrane reactor; thus, rendering possible a future preparative scale for this synthesis and for the dehydrogenation of numerous other (2R)-hydroxycarboxylates. (C) Elsevier Science Inc. All rights reserved.