DECHEMA

About: DECHEMA is a nonprofit organization based out in Frankfurt am Main, Germany. It is known for research contribution in the topics: Corrosion & Oxide. The organization has 756 authors who have published 1307 publications receiving 25693 citations.

Thioesterases for ethylmalonyl–CoA pathway derived dicarboxylic acid production in Methylobacterium extorquens AM1

Abstract: The ethylmalonyl–coenzyme A pathway (EMCP) is a recently discovered pathway present in diverse α-proteobacteria such as the well studied methylotroph Methylobacterium extorquens AM1. Its glyoxylate regeneration function is obligatory during growth on C1 carbon sources like methanol. The EMCP contains special CoA esters, of which dicarboxylic acid derivatives are of high interest as building blocks for chemical industry. The possible production of dicarboxylic acids out of the alternative, non-food competing C-source methanol could lead to sustainable and economic processes. In this work we present a testing of functional thioesterases being active towards the EMCP CoA esters including in vitro enzymatic assays and in vivo acid production. Five thioesterases including TesB from Escherichia coli and M. extorquens, YciA from E. coli, Bch from Bacillus subtilis and Acot4 from Mus musculus showed activity towards EMCP CoA esters in vitro at which YciA was most active. Expressing yciA in M. extorquens AM1 led to release of 70 mg/l mesaconic and 60 mg/l methylsuccinic acid into culture supernatant during exponential growth phase. Our data demonstrates the biotechnological applicability of the thioesterase YciA and the possibility of EMCP dicarboxylic acid production from methanol using M. extorquens AM1.

Process engineering for bioflavour production with metabolically active yeasts – a mini-review

Abstract: Flavours are biologically active molecules of large commercial interest in the food, cosmetics, detergent and pharmaceutical industries. The production of flavours can take place by either extraction from plant materials, chemical synthesis, biological conversion of precursor molecules or de novo biosynthesis. The latter alternatives are gaining importance through the rapidly growing fields of systems biology and metabolic engineering, giving efficient production hosts for the so-called 'bioflavours', which are natural flavour and/or fragrance compounds obtained with cell factories or enzymatic systems. Yeasts are potential production hosts for bioflavours. In this mini-review, we give an overview of bioflavour production in yeasts from the process-engineering perspective. Two specific examples, production of 2-phenylethanol and vanillin, are used to illustrate the process challenges and strategies used.

Corrosion of Metals in Organic Solvents

Abstract: Developments in the chemical and petrochemical industries, advances in chemical engineering, the introduction of new products, advances in the technology of intermediates, and problems in energy conversion have created new corrosion problems, involving the failure of metallic materials under the influence of aggressive organic solvents. Failures of this type lead not only to a deterioration of the mechanical properties of structural material, but also to discoloration and unwanted changes of the solvent. Since organic solvents in most cases are poisonous, inflammable, and, in the presence of air, explosive, the demands on the corrosion resistance of the materials used are immense. Therefore, in discussing corrosion of metals in organic solvents problems arise which have no parallel in the field of corrosion in aqueous media.

Cascading g-C3N4 and Peroxygenases for Selective Oxyfunctionalization Reactions

Abstract: Peroxygenases are very interesting catalysts for specific oxyfunctionalization chemistry. Instead of relying on complicated electron transport chains, they rely on simple hydrogen peroxide as the stoichiometric oxidant. Their poor robustness against H2O2 can be addressed via in situ generation of H2O2. Here we report that simple graphitic carbon nitride (g-C3N4) is a promising photocatalyst to drive peroxygenase-catalyzed hydroxylation reactions. The system has been characterized by outlining not only its scope but also its current limitations. In particular, spatial separation of the photocatalyst from the enzyme is shown as a solution to circumvent the undesired inactivation of the biocatalyst. Overall, very promising turnover numbers of the biocatalyst of more than 60.000 have been achieved.