Synthesis of α-hydroxy ketones and vicinal diols with the Bacillus licheniformis DSM 13 butane-2,3-diol dehydrogenase.

The enantioselective synthesis of α-hydroxy ketones and vicinal diols is an intriguing field because of the broad applicability of these molecules. Although, butandiol dehydrogenases are known to play a key role in the production of 2,3-butandiol, their potential as biocatalysts is still not well studied. Here, we investigate the biocatalytic properties of the meso-butanediol dehydrogenase from Bacillus licheniformis DSM 13 (BlBDH).

Synthesis of α-hydroxy ketones and vicinal (,)-diols by DSM 8716 butanediol dehydrogenase.

α-hydroxy ketones (HK) and 1,2-diols are important building blocks for fine chemical synthesis. Here, we describe the -selective 2,3-butanediol dehydrogenase from DSM 8716 (BcBDH) that belongs to the metal-dependent medium chain dehydrogenases/reductases family (MDR) and catalyzes the selective asymmetric reduction of prochiral 1,2-diketones to the corresponding HK and, in some cases, the reduction of the same to the corresponding 1,2-diols. Aliphatic diketones, like 2,3-pentanedione, 2,3-hexanedione, 5-methyl-2,3-hexanedione, 3,4-hexanedione and 2,3-heptanedione are well transformed.

Screen-Printed Carbon Electrodes Modified with Graphene Oxide for the Design of a Reagent-Free NAD-Dependent Biosensor Array.

A facile approach for the construction of reagent-free electrochemical dehydrogenase-based biosensors is presented. Enzymes and cofactors (NAD and Fe(CN)) were immobilized by modification of screen-printed carbon electrodes with graphene oxide (GO) and an additional layer of cellulose acetate. The sensor system was exemplarily optimized for an l-lactate electrode in terms of GO concentration, working potential, and pH value.

Combinatorial assembly of ferredoxin-linked modules in Escherichia coli yields a testing platform for Rnf-complexes.

The Rnf complex is a membrane-bound ferredoxin(Fd):NAD(P) oxidoreductase (Fno) that couples Fd oxidation to vectorial H /Na transport across the cytoplasmic membrane. Here, we produced two putative Rnf-complexes from Clostridioides difficile (Cd-Rnf) and Clostridium ljungdahlii (Cl-Rnf) for the first time in Escherichia coli. A redox-responsive low-expression system enabled Rnf assembly in the membranes of E.

Quantitative differential monitoring of the metabolic activity of Corynebacterium glutamicum cultures utilizing a light-addressable potentiometric sensor system.

Applying biosensors for evaluation of the extracellular acidification of microorganisms in various biotechnological fermentation processes is on demand. An early stage detection of disturbances in the production line would avoid costly interventions related to metabolically inactive microorganisms. Furthermore, the determination of the number of living cells through cell plating procedure after cultivations is known as time- and material-consuming.