title: Immobilization of membrane-bounded (S)-mandelate dehydrogenase in sol-gel matrix for electroenzymatic synthesis.
abstract: Membrane-bounded (S)-mandelate dehydrogenase has been immobilized on the surface of glassy carbon and carbon felt electrodes by encapsulation in a silica film obtained by sol-gel chemistry. Such bioelectrochemical system has been used for the first time for electroenzymatic conversion of (S)-mandelic acid to phenylglyoxylic acid. Apparent Km in this sol-gel matrix was 0.7 mM in the presence of ferrocenedimethanol, a value in the same order of magnitude as reported previously for vesicles in solution with other electron acceptors, i.e., Fe(CN)6(3-) or 2,6-dichloroindophenol. The bioelectrode shows very good operational stability for more than 6 days. This stability was definitively improved by comparison to a bioelectrode prepared by simple adsorption of the proteins on the electrode surface (fast activity decrease during the first 15 h of experiment). Optimal electroenzymatic reaction was achieved at pH9 and 40 °C. Apparent Km of the protein activity was 3 times higher in carbon felt electrode than on glassy carbon surface, possibly because of transport limitations in the porous architecture of the carbon felt. A good correlation was found between electrochemical data and chromatographic characterization of the reaction products in the bioelectrochemical reactor.
authors: CNRS, LCPME, UMR7564, 405 rue de Vandoeuvre, F-54600 Villers-lès-Nancy, France; Université de Lorraine, LCPME, UMR7564, 405 rue de Vandoeuvre, F-54600 Villers-lès-Nancy, France.
authors: Ievgen
authors: I
authors: Mazurenko
authors: CNRS, LCPME, UMR7564, 405 rue de Vandoeuvre, F-54600 Villers-lès-Nancy, France; Université de Lorraine, LCPME, UMR7564, 405 rue de Vandoeuvre, F-54600 Villers-lès-Nancy, France.
authors: Wissam
authors: W
authors: Ghach
authors: Microbiology, Saarland University, Campus, Geb. A1.5, D-66123 Saarbruecken, Germany.
authors: Gert-Wieland
authors: GW
authors: Kohring
authors: CNRS, LCPME, UMR7564, 405 rue de Vandoeuvre, F-54600 Villers-lès-Nancy, France; Université de Lorraine, LCPME, UMR7564, 405 rue de Vandoeuvre, F-54600 Villers-lès-Nancy, France.
authors: Christelle
authors: C
authors: Despas
authors: CNRS, LCPME, UMR7564, 405 rue de Vandoeuvre, F-54600 Villers-lès-Nancy, France; Université de Lorraine, LCPME, UMR7564, 405 rue de Vandoeuvre, F-54600 Villers-lès-Nancy, France.
authors: Alain
authors: A
authors: Walcarius
authors: CNRS, LCPME, UMR7564, 405 rue de Vandoeuvre, F-54600 Villers-lès-Nancy, France; Université de Lorraine, LCPME, UMR7564, 405 rue de Vandoeuvre, F-54600 Villers-lès-Nancy, France. Electronic address: mathieu.etienne@univ-lorraine.fr.
authors: Mathieu
authors: M
authors: Etienne
mesh_terms: D000429:Alcohol Oxidoreductases / Q000737:chemistry* / Q000378:metabolism; D002244:Carbon / Q000737:chemistry; D004563:Electrochemistry; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism; D005898:Glass / Q000737:chemistry; D006038:Glyoxylates / Q000737:chemistry; D008333:Mandelic Acids / Q000737:chemistry; D008567:Membranes, Artificial; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D004800:Enzymes, Immobilized; D006038:Glyoxylates; D008333:Mandelic Acids; D008567:Membranes, Artificial; C012482:phenylglyoxylic acid; D002244:Carbon; D012822:Silicon Dioxide; D000429:Alcohol Oxidoreductases; C021538:L-mandelate dehydrogenase; C037938:mandelic acid
keywords: Bioelectrochemical system; Electrosynthesis; Membrane protein; Sol–gel