Oxygen uptake rates in the hyperthermophilic anaerobe Thermotoga maritima grown in a bioreactor under controlled oxygen exposure: clues to its defence strategy against oxidative stress.

A 2.3-L bioreactor was specially adapted to grow hyperthermophilic microorganisms under controlled conditions of temperature, pH, redox potential and dissolved O(2). Using this bioreactor regulated at 80°C and pH 7.

Response of Desulfovibrio vulgaris Hildenborough to hydrogen peroxide: enzymatic and transcriptional analyses.

We studied the effect of hydrogen peroxide (H(2)O(2)) stress on the anaerobic sulfate-reducing bacterium Desulfovibrio vulgaris Hildenborough. In a lactate/sulfate medium, growth was affected from 0.1 mM H(2)O(2) and totally inhibited at 0.

Molybdenum induces the expression of a protein containing a new heterometallic Mo-Fe cluster in Desulfovibrio alaskensis.

The characterization of a novel Mo-Fe protein (MorP) associated with a system that responds to Mo in Desulfovibrio alaskensis is reported. Biochemical characterization shows that MorP is a periplasmic homomultimer of high molecular weight (260 +/- 13 kDa) consisting of 16-18 monomers of 15321.1 +/- 0.

Crystal structure of the 16 heme cytochrome from Desulfovibrio gigas: a glycosylated protein in a sulphate-reducing bacterium.

Sulphate-reducing bacteria have a wide variety of periplasmic cytochromes involved in electron transfer from the periplasm to the cytoplasm. HmcA is a high molecular mass cytochrome of 550 amino acid residues that harbours 16 c-type heme groups. We report the crystal structure of HmcA isolated from the periplasm of Desulfovibrio gigas.

Role of the tetrahemic subunit in Desulfovibrio vulgaris hildenborough formate dehydrogenase.

In the anaerobic sulfate-reducing bacterium Desulfovibrio vulgaris Hildenborough (DvH), the genome sequencing revealed the presence of three operons encoding formate dehydrogenases. fdh1 encodes an alphabetagamma trimeric enzyme containing 11 heme binding sites; fdh2 corresponds to an alphabetagamma trimeric enzyme with a tetrahemic subunit; fdh3 encodes an alphabeta dimeric enzyme. In the present work, spectroscopic measurements demonstrated that the reduction of cytochrome c(553) was obtained in the presence of the trimeric FDH2 and not with the dimeric FDH3, suggesting that the tetrahemic subunit (FDH2C) is essential for the interaction with this physiological electron transfer partner.

Response of the anaerobe Desulfovibrio vulgaris Hildenborough to oxidative conditions: proteome and transcript analysis.

The method of two-dimensional protein gel electrophoresis was used to evaluate the changes at the proteins level following oxygen exposure of the anaerobic sulfate-reducing bacterium Desulfovibrio vulgaris Hildenborough. Fifty-seven proteins showed significant differential expression. The cellular concentration of 35 proteins decreased while that of nineteen increased as a specific consequence of oxidative conditions.

A new function of the Desulfovibrio vulgaris Hildenborough [Fe] hydrogenase in the protection against oxidative stress.

Sulfate-reducing bacteria, like Desulfovibrio vulgaris Hildenborough, have developed a set of reactions allowing them to survive in oxic environments and even to reduce molecular oxygen to water. D. vulgaris contains a cytoplasmic superoxide reductase (SOR) and a periplasmic superoxide dismutase (SOD) involved in the elimination of superoxide anions.

The naphthoquinol oxidizing cytochrome bc1 complex of the hyperthermophilic knallgasbacterium Aquifex aeolicus: properties and phylogenetic relationships.

Phylogenetic analysis of constituent proteins of Rieske/cytochrome b complexes [Schütz et al. (2000) J. Mol.

A quick solution structure determination of the fully oxidized double mutant K9-10A cytochrome c7 from Desulfuromonas acetoxidans and mechanistic implications.

Lysines 9 and 10 in Desulfuromonas acetoxidans cytochrome c7, which could be involved in the interaction mechanism with the redox partners, have been replaced by alanine residues using site-directed mutagenesis. The solution structure of the fully oxidized form of K9-10A cytochrome c7, which is paramagnetic with three paramagnetic centers, has been determined via 1H NMR. The assignment of the spectra has been performed through an automatic program whose algorithm and strategy are here described.