The effect of host plant cultivar on H2 evolution by root nodules was examined in symbioses between Pisum sativum L. and selected strains of Rhizobium leguminosarum. Hydrogen evolution from root nodules containing Rhizobium represents the sum of H2 produced by the nitrogenase enzyme complex and H2 oxidized by any uptake hydrogenase present in those bacterial cells. Relative efficiency (RE) calc...

Function of Ech hydrogenase in ferredoxin-dependent, membrane-bound electron transport in Methanosarcina mazei.

Cells Sergey V. Morozov, Arkady A. Karyakin, Paulette M. Vignais, Serge Cosnier Faculty of Chemistry, M.V.Lomonosov Moscow State University, 119992, Moscow, Russia CEA/Grenoble, BBSI (UMR CEA/CNRS/UJF no. 5092), DRDC, 38054 Grenoble Cedex 9, France 3 LEOPR (UMR CNRS no. 5630), UJF, BP 53, 38041 Grenoble Cedex 9, France Molecular hydrogen is considered nowadays as the most promising chemical fue...

This report deals with the relationship between liver L-Alanine: 2-oxoglutarate aminotransferaes ( EC 2. 6. 1. 2) activity and RES function. In fasted rats, decrease in .d4-3-ketost eroid hydrogenase ( EC 1. 3. 1. 3 and 1. 3. 1. 4) and phagocytic activity and increase in alanine aminotransferase activity wer e noted. On the other hand, increase in Ll4-3-ketost eroid hydrogenase and phagocytic a...

An azadithiolate bridged monocyanide derivative [Fe2(adt)(CO)5(CN)]- of [Fe2(adt)(CO)4(CN)2]2- has been prepared and extensively characterized as a model of the [FeFe]-hydrogenase active site, using a combination of FTIR spectroscopy, electrochemical methods and catalytic assays with chemical reductants. The presence of two basic nitrogen sites opens up multiple protonation pathways, enabling c...

Hydrogen (H 2 ) is a promising future chemical energy carrier and feedstock with several renewable production options, including electrolyzers biological/bioinspired systems. The top H producers in nature are [FeFe]-hydrogenases, high turnover metalloenzymes complex maturation process that can be circumvented by artificial synthetic activation. Here, we report the expression activation of group...

High-level synthesis of complex enzymes like bacterial [NiFe] hydrogenases, in general, requires an expression system that allows concerted expression of a large number of genes. So far, it has not been possible to overproduce a hydrogenase in a stable and active form by using a customary expression system. Therefore we started to establish a new, T(7)-based expression system in the phototrophi...

Buller, C. S. (University of Kansas, Lawrence), and J. M. Akagi. Hydrogenase of Coleman's sulfate-reducing bacterium. J. Bacteriol. 88:440-443. 1964.-The hydrogenase of the Coleman organism was found to be associated with the particulate fraction of cell-free extracts. This enzyme catalyzed the oxidation of molecular hydrogen in the presence of various electron acceptors. It was also able to ev...

Hydrogenase and the adenosine 5'-triphosphate (ATP) synthetase complex, two enzymes essential in ATP generation in Methanobacterium thermoautotrophicum, were localized in internal membrane systems as shown by cytochemical techniques. Membrane vesicles from this organism possessed hydrogenase and adenosine triphosphatase (ATPase) activity and synthesized ATP driven by hydrogen oxidation or a pot...