The hyperthermophilic and anaerobic bacterium Thermotoga maritima ferments a wide variety of carbohydrates, producing acetate, CO(2), and H(2). Glucose is degraded through a classical Embden-Meyerhof pathway, and both NADH and reduced ferredoxin are generated. The oxidation of these electron carriers must be coupled to H(2) production, but the mechanism by which this occurs is unknown. The trim...

During recenit years considerable attenitioni lhas l)een focused on the role of non-hcaemii proteinis conItaining iron in biological electron transfer sVstemis. Several proteins of this type showving idenitical catalytic properties have been isolated froimi greeni cells (6). These proteinis, w-hich are localized in the chloroplasts, include the methaemoglobinl re(luciing factor (5) from parsley...

Archaebacterium, Methanosarcina, Methanol, Iron, Mössbauer, Ferredoxin Cells of the archaebacterium Methanosarcina barkeri were grown strictly anaerobic in defined media. 57Fe-Mössbauer Spectroscopy of methanol grown cells oxidized in the presence of air demonstrated only the state of Fe3+ whereas active cells under reducing conditions offered spectra of two additional iron sites in the Fe2+ st...

The tungsten metallome of the hyperthermophilic archaeon Pyrococcus furiosus has been investigated using electroanalytical metal analysis and native-native 2D-PAGE with the radioactive tungsten isotope (187)W (t(1/2) = 23.9 h). P. furiosus cells have an intracellular tungsten concentration of 29 μM, of which ca. 30% appears to be free tungsten, probably in the form of tungstate or polytungstate...

Assimilatory nitrate reductase was particle-bound in extracts from Azotobacter vinelandii. Nitrate reduction by particle fractions was dependent on NADPH and a particle-bound electron carrier. When the enzyme was solubilized from the particles by treatment with detergents, the particle-bound electron carrier could be substituted by ferredoxin or flavodoxin. Flavodoxin reduced at the expense of ...