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.

Use of an oxygen gas diffusion cathode and a three-dimensional packed bed anode in a bioelectrochemical fuel cell

Abstract: An oxygen gas diffusion electrode was successfully used as a cathode in a bioelectro-chemical fuel cell with 2-hydroxy-1,4-naphthoquinone as redox-mediator and Escherichia coli as biocatalyst. On addition of bacteria to the anode compartment of the fuel cell a rapid increase in the electricity output was observed. With the use of a three-dimensional packed bed anode the electricity output of the cell could be considerably increased.

Improvement of the oxidation resistance of TiAl alloys by using the chlorine effect

Abstract: Most TiAl alloys lack from their insufficient oxidation resistance in air at temperatures above 800°C. Recently it has been found that small amounts of Cl in the alloy may significantly improve the oxidation resistance. However, the mechanisms responsible for this effect were not yet understood. In the paper oxidation experiments with TiAl alloys are reported where Cl was alloyed to the material by the P/M route or applied to the material surface either by ion implantation or by PVD. The results of the investigations revealed that the Cl-effect is due to the formation of volatile metal chloride species. It is shown that chlorine can have a beneficial effect on oxidation resistance in a certain Cl-range which is quantified by thermodynamic calculations. It is assumed that the Cl-effect offers a significant potential for improvement of the oxidation resistance of technical TiAl alloys.

Improvement of P450BM-3 whole-cell biocatalysis by integrating heterologous cofactor regeneration combining glucose facilitator and dehydrogenase in E. coli

Abstract: Escherichia coli BL21, expressing a quintuple mutant of P450BM-3, oxyfunctionalizes α-pinene in an NADPH-dependent reaction to α-pinene oxide, verbenol, and myrtenol. We optimized the whole-cell biocatalyst by integrating a recombinant intracellular NADPH regeneration system through co-expression of a glucose facilitator from Zymomonas mobilis for uptake of unphosphorylated glucose and a NADP+-dependent glucose dehydrogenase from Bacillus megaterium that oxidizes glucose to gluconolactone. The engineered strain showed a nine times higher initial α-pinene oxide formation rate corresponding to a sixfold higher yield of 20 mg g−1 cell dry weight after 1.5 h. The initial total product formation rate was 1,000 μmol h−1 μmol−1 P450 leading to a total of 32 mg oxidized products per gram cell of dry weight after 1.5 h. The physiological functioning of the heterologous cofactor regeneration system was illustrated by a sevenfold increased α-pinene oxide yield in the presence of glucose compared to glucose-free conditions.